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MuiInputBase-sizeSmall MuiInputBase-adornedStart css-10r6rap"><div class="MuiInputAdornment-root MuiInputAdornment-positionStart MuiInputAdornment-outlined MuiInputAdornment-sizeSmall css-1a6giau"><span class="notranslate"></span><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeSmall css-1k33q06" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="SearchIcon"><path d="M15.5 14h-.79l-.28-.27C15.41 12.59 16 11.11 16 9.5 16 5.91 13.09 3 9.5 3S3 5.91 3 9.5 5.91 16 9.5 16c1.61 0 3.09-.59 4.23-1.57l.27.28v.79l5 4.99L20.49 19l-4.99-5zm-6 0C7.01 14 5 11.99 5 9.5S7.01 5 9.5 5 14 7.01 14 9.5 11.99 14 9.5 14z"/></svg></div><input type="search" aria-invalid="false" id="doc-search" placeholder="搜索文档" value="" class="MuiInputBase-input MuiOutlinedInput-input MuiInputBase-inputTypeSearch MuiInputBase-inputSizeSmall MuiInputBase-inputAdornedStart css-1a7iucg"/><fieldset aria-hidden="true" class="MuiOutlinedInput-notchedOutline css-igs3ac"><legend class="css-hdw1oc"><span class="notranslate"></span></legend></fieldset></div></div></form></div></div></div></div></header><div class="PingCAP-Doc MuiBox-root css-s1brf2"><div class="MuiBox-root css-hboir5"><aside class="MuiBox-root css-2tzg8"><div class="MuiBox-root css-ysaqso"><button class="MuiButtonBase-root MuiButton-root MuiButton-text MuiButton-textPrimary MuiButton-sizeMedium MuiButton-textSizeMedium MuiButton-disableElevation css-1q0sqyi" tabindex="0" type="button" id="version-select-button" aria-haspopup="true"><div class="MuiTypography-root MuiTypography-body1 css-1alj0g7">v6.1</div><span class="MuiButton-endIcon MuiButton-iconSizeMedium css-pt151d"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium css-1rrdqpg" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg></span></button><ul role="tree" id="left-nav-treeview" aria-multiselectable="false" class="MuiTreeView-root css-12mehxg" tabindex="0" aria-label="left navigation"><a class="MuiTypography-root MuiTypography-body1 css-ae3kd9" target="_blank" href="https://docs.pingcap.com/zh" style="text-decoration:none;width:100%;color:inherit"><li class="MuiTreeItem-root css-14t19hb" role="treeitem" id="left-nav-treeview-0-0" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-w8t2sr"><div class="MuiBox-root css-3o0h5k"/><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1drfgi3">文档中心</div></div></div></div></div></li></a><li class="MuiTreeItem-root css-14t19hb" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-1" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-w8t2sr"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-hkir54" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1drfgi3">关于 TiDB</div></div></div></div></div></li><li class="MuiTreeItem-root css-14t19hb" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-2" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-w8t2sr"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-hkir54" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1drfgi3">快速上手</div></div></div></div></div></li><li class="MuiTreeItem-root css-14t19hb" role="treeitem" aria-expanded="true" id="left-nav-treeview-0-3" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-fhn3dm MuiTreeItem-content Mui-expanded" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-w8t2sr"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-13dmm4z" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1drfgi3">应用开发</div></div></div></div></div><ul class="MuiCollapse-root MuiCollapse-vertical MuiTreeItem-group MuiCollapse-entered css-1xxsnna" style="min-height:0px" role="group"><div class="MuiCollapse-wrapper MuiCollapse-vertical css-hboir5"><div class="MuiCollapse-wrapperInner MuiCollapse-vertical css-8atqhb"><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/v6.1/dev-guide-overview"><li class="MuiTreeItem-root css-14t19hb" role="treeitem" id="left-nav-treeview-0-3-0" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-2jyri7"><div class="MuiBox-root css-3o0h5k"/><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1drfgi3">概览</div></div></div></div></div></li></a><li class="MuiTreeItem-root css-14t19hb" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-3-1" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-2jyri7"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-hkir54" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1drfgi3">快速开始</div></div></div></div></div></li><li class="MuiTreeItem-root css-14t19hb" role="treeitem" aria-expanded="true" id="left-nav-treeview-0-3-2" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-fhn3dm MuiTreeItem-content Mui-expanded" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-2jyri7"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-13dmm4z" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1drfgi3">示例程序</div></div></div></div></div><ul class="MuiCollapse-root MuiCollapse-vertical MuiTreeItem-group MuiCollapse-entered css-1xxsnna" style="min-height:0px" role="group"><div class="MuiCollapse-wrapper MuiCollapse-vertical css-hboir5"><div class="MuiCollapse-wrapperInner MuiCollapse-vertical css-8atqhb"><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/v6.1/dev-guide-sample-application-golang"><li class="MuiTreeItem-root css-14t19hb" role="treeitem" id="left-nav-treeview-0-3-2-0" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-xeut16"><div class="MuiBox-root css-3o0h5k"/><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1drfgi3">Golang</div></div></div></div></div></li></a><a aria-current="page" style="text-decoration:none;width:100%;color:inherit" class="" href="/zh/tidb/v6.1/dev-guide-sample-application-spring-boot"><li class="MuiTreeItem-root css-14t19hb" role="treeitem" aria-selected="true" id="left-nav-treeview-0-3-2-1" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-fhn3dm MuiTreeItem-content Mui-expanded Mui-selected" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-xeut16"><div class="MuiBox-root css-3o0h5k"/><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1drfgi3">Java (Spring Boot)</div></div></div></div></div></li></a><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/v6.1/dev-guide-sample-application-java"><li class="MuiTreeItem-root css-14t19hb" role="treeitem" id="left-nav-treeview-0-3-2-2" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-xeut16"><div class="MuiBox-root css-3o0h5k"/><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1drfgi3">Java</div></div></div></div></div></li></a><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/v6.1/dev-guide-sample-application-django"><li class="MuiTreeItem-root css-14t19hb" role="treeitem" id="left-nav-treeview-0-3-2-3" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-xeut16"><div class="MuiBox-root css-3o0h5k"/><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1drfgi3">Python (Django)</div></div></div></div></div></li></a><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/v6.1/dev-guide-sample-application-python"><li class="MuiTreeItem-root css-14t19hb" role="treeitem" id="left-nav-treeview-0-3-2-4" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-xeut16"><div class="MuiBox-root css-3o0h5k"/><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1drfgi3">Python</div></div></div></div></div></li></a></div></div></ul></li><li class="MuiTreeItem-root css-14t19hb" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-3-3" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-2jyri7"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-hkir54" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1drfgi3">连接到 TiDB</div></div></div></div></div></li><li class="MuiTreeItem-root css-14t19hb" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-3-4" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-2jyri7"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-hkir54" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1drfgi3">数据库模式设计</div></div></div></div></div></li><li class="MuiTreeItem-root css-14t19hb" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-3-5" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-2jyri7"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-hkir54" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1drfgi3">数据写入</div></div></div></div></div></li><li class="MuiTreeItem-root css-14t19hb" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-3-6" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-2jyri7"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-hkir54" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1drfgi3">数据读取</div></div></div></div></div></li><li class="MuiTreeItem-root css-14t19hb" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-3-7" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-2jyri7"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-hkir54" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1drfgi3">事务</div></div></div></div></div></li><li class="MuiTreeItem-root css-14t19hb" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-3-8" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-2jyri7"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-hkir54" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1drfgi3">优化 SQL 性能</div></div></div></div></div></li><li class="MuiTreeItem-root css-14t19hb" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-3-9" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-2jyri7"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-hkir54" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1drfgi3">故障诊断</div></div></div></div></div></li><li class="MuiTreeItem-root css-14t19hb" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-3-10" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-2jyri7"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-hkir54" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1drfgi3">引用文档</div></div></div></div></div></li><li class="MuiTreeItem-root css-14t19hb" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-3-11" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-2jyri7"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-hkir54" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1drfgi3">云原生开发环境</div></div></div></div></div></li><li class="MuiTreeItem-root css-14t19hb" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-3-12" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-2jyri7"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-hkir54" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1drfgi3">第三方工具支持</div></div></div></div></div></li></div></div></ul></li><li class="MuiTreeItem-root css-14t19hb" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-4" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-w8t2sr"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-hkir54" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1drfgi3">部署标准集群</div></div></div></div></div></li><li class="MuiTreeItem-root css-14t19hb" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-5" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-w8t2sr"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-hkir54" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1drfgi3">数据迁移</div></div></div></div></div></li><li class="MuiTreeItem-root css-14t19hb" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-6" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-w8t2sr"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-hkir54" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1drfgi3">数据集成</div></div></div></div></div></li><li class="MuiTreeItem-root css-14t19hb" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-7" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-w8t2sr"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-hkir54" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1drfgi3">运维操作</div></div></div></div></div></li><li class="MuiTreeItem-root css-14t19hb" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-8" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-w8t2sr"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-hkir54" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1drfgi3">监控与告警</div></div></div></div></div></li><li class="MuiTreeItem-root css-14t19hb" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-9" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-w8t2sr"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-hkir54" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1drfgi3">故障诊断</div></div></div></div></div></li><li class="MuiTreeItem-root css-14t19hb" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-10" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-w8t2sr"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-hkir54" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1drfgi3">性能调优</div></div></div></div></div></li><li class="MuiTreeItem-root css-14t19hb" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-11" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-w8t2sr"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-hkir54" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1drfgi3">教程</div></div></div></div></div></li><li class="MuiTreeItem-root css-14t19hb" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-12" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-w8t2sr"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-hkir54" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1drfgi3">TiDB 工具</div></div></div></div></div></li><li class="MuiTreeItem-root css-14t19hb" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-13" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-w8t2sr"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-hkir54" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1drfgi3">参考指南</div></div></div></div></div></li><li class="MuiTreeItem-root css-14t19hb" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-14" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-w8t2sr"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-hkir54" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1drfgi3">常见问题解答 (FAQ)</div></div></div></div></div></li><li class="MuiTreeItem-root css-14t19hb" role="treeitem" aria-expanded="false" id="left-nav-treeview-0-15" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-w8t2sr"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium MuiTreeItem-ChevronRightIcon css-hkir54" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ChevronRightIcon"><path d="M10 6 8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"/></svg><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1drfgi3">版本发布历史</div></div></div></div></div></li><a style="text-decoration:none;width:100%;color:inherit" href="/zh/tidb/v6.1/glossary"><li class="MuiTreeItem-root css-14t19hb" role="treeitem" id="left-nav-treeview-0-16" tabindex="-1" style="margin-top:0.1875rem;margin-bottom:0.1875rem"><div class="css-fhn3dm MuiTreeItem-content" style="width:inherit"><div class="MuiTreeItem-iconContainer"/><div class="MuiTreeItem-label"><div class="css-w8t2sr"><div class="MuiBox-root css-3o0h5k"/><div class="MuiBox-root css-8atqhb"><div class="MuiTypography-root MuiTypography-body1 css-1drfgi3">术语表</div></div></div></div></div></li></a></ul></div></aside><main class="MuiBox-root css-sb2sd0"><div class="MuiBox-root css-w0vdto"><div class="css-1q5cbag"><div class="MuiBox-root css-was4pq"><div class="MuiContainer-root MuiContainer-maxWidthLg MuiContainer-disableGutters doc-content css-5csqms"><div class="markdown-body MuiBox-root css-0"><h1 id="使用-spring-boot-构建-tidb-应用程序" style="position:relative">使用 Spring Boot 构建 TiDB 应用程序<a href="#%E4%BD%BF%E7%94%A8-spring-boot-%E6%9E%84%E5%BB%BA-tidb-%E5%BA%94%E7%94%A8%E7%A8%8B%E5%BA%8F" aria-label="使用 spring boot 构建 tidb 应用程序 permalink" class="anchor after"><svg aria-hidden="true" focusable="false" height="16" version="1.1" viewbox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"/></svg></a></h1><p>本教程向你展示如何使用 TiDB 构建 <a href="https://spring.io/projects/spring-boot" target="_blank" referrerpolicy="no-referrer-when-downgrade">Spring Boot</a> Web 应用程序。使用 <a href="https://spring.io/projects/spring-data-jpa" target="_blank" referrerpolicy="no-referrer-when-downgrade">Spring Data JPA</a> 模块作为数据访问能力的框架。此示例应用程序的代码仓库可在 <a href="https://github.com/pingcap-inc/tidb-example-java" target="_blank" referrerpolicy="no-referrer-when-downgrade">Github</a> 下载。</p><p>这是一个较为完整的构建 Restful API 的示例应用程序，展示了一个使用 <strong>TiDB</strong> 作为数据库的通用 <strong>Spring Boot</strong> 后端服务。设计了以下过程，用于还原一个现实场景：</p><p>这是一个关于游戏的例子，每个玩家有两个属性：金币数 <code>coins</code> 和货物数 <code>goods</code>。且每个玩家都拥有一个字段 <code>id</code>，作为玩家的唯一标识。玩家在金币数和货物数充足的情况下，可以自由的交易。</p><p>你可以以此示例为基础，构建自己的应用程序。</p><div class="MuiBox-root css-1weqspv"><div class="MuiPaper-root MuiPaper-elevation MuiPaper-rounded MuiPaper-elevation0 MuiAlert-root MuiAlert-standardSuccess MuiAlert-standard css-9c4k42" role="alert"><div class="MuiAlert-icon css-1l54tgj"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium css-vubbuv" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="AttachmentIcon"><path d="M2 12.5C2 9.46 4.46 7 7.5 7H18c2.21 0 4 1.79 4 4s-1.79 4-4 4H9.5C8.12 15 7 13.88 7 12.5S8.12 10 9.5 10H17v2H9.41c-.55 0-.55 1 0 1H18c1.1 0 2-.9 2-2s-.9-2-2-2H7.5C5.57 9 4 10.57 4 12.5S5.57 16 7.5 16H17v2H7.5C4.46 18 2 15.54 2 12.5z"/></svg></div><div class="MuiAlert-message css-1xsto0d"><div class="MuiTypography-root MuiTypography-body1 MuiTypography-gutterBottom MuiAlertTitle-root css-m00e13">小贴士</div><p>在<a href="/zh/tidb/v6.1/dev-guide-playground-gitpod">云原生开发环境</a>中尝试 Spring Boot 构建 TiDB 应用程序。预配置完成的环境，自动启动 TiDB 集群，获取和运行代码，只需要一个链接。</p><p><a href="https://gitpod.io/#targetFile=spring-jpa-hibernate_Makefile,targetMode=spring-jpa-hibernate/https://github.com/pingcap-inc/tidb-example-java" target="_blank" referrerpolicy="no-referrer-when-downgrade">现在就试试</a></p></div></div></div><h2 id="第-1-步启动你的-tidb-集群" style="position:relative">第 1 步：启动你的 TiDB 集群<a href="#%E7%AC%AC-1-%E6%AD%A5%E5%90%AF%E5%8A%A8%E4%BD%A0%E7%9A%84-tidb-%E9%9B%86%E7%BE%A4" aria-label="第 1 步启动你的 tidb 集群 permalink" class="anchor after"><svg aria-hidden="true" focusable="false" height="16" version="1.1" viewbox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"/></svg></a></h2><p>本节将介绍 TiDB 集群的启动方法。</p><ul class="simple-tab-module--tabs--tXejZ simple-tab-container"><li class="simple-tab-module--active--dcjQ4">TiDB Cloud</li><li class="">本地集群</li><li class="">Gitpod</li></ul><div class=""><p><a href="/zh/tidb/v6.1/dev-guide-build-cluster-in-cloud#第-1-步创建-tidb-serverless-集群">创建 TiDB Serverless 集群</a>。</p></div><div class="simple-tab-module--hidden--xELDk"><p>你可以部署一个本地测试的 TiDB 集群或正式的 TiDB 集群。详细步骤，请参考：</p><ul><li><a href="/zh/tidb/v6.1/quick-start-with-tidb#部署本地测试集群">部署本地测试 TiDB 集群</a></li><li><a href="/zh/tidb/v6.1/production-deployment-using-tiup">部署正式 TiDB 集群</a></li></ul></div><div class="simple-tab-module--hidden--xELDk"><p>基于 Git 的预配置的开发环境：<a href="/zh/tidb/v6.1/dev-guide-playground-gitpod">现在就试试</a></p><p>该环境会自动克隆代码，并通过 TiUP 部署测试集群。</p></div><h2 id="第-2-步安装-jdk" style="position:relative">第 2 步：安装 JDK<a href="#%E7%AC%AC-2-%E6%AD%A5%E5%AE%89%E8%A3%85-jdk" aria-label="第 2 步安装 jdk permalink" class="anchor after"><svg aria-hidden="true" focusable="false" height="16" version="1.1" viewbox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"/></svg></a></h2><p>请在你的计算机上下载并安装 <strong>Java Development Kit</strong> (JDK)，这是 Java 开发的必备工具。<strong>Spring Boot</strong> 支持 Java 版本 8 以上的 JDK，由于 <strong>Hibernate</strong> 版本的缘故，推荐使用 Java 版本 11 以上的 JDK 。</p><p>示例应用程序同时支持 <strong>Oracle JDK</strong> 和 <strong>OpenJDK</strong>，请自行选择，本教程将使用版本 17 的 <strong>OpenJDK</strong> 。</p><h2 id="第-3-步安装-maven" style="position:relative">第 3 步：安装 Maven<a href="#%E7%AC%AC-3-%E6%AD%A5%E5%AE%89%E8%A3%85-maven" aria-label="第 3 步安装 maven permalink" class="anchor after"><svg aria-hidden="true" focusable="false" height="16" version="1.1" viewbox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"/></svg></a></h2><p>此示例应用程序使用 <strong>Maven</strong> 来管理应用程序的依赖项。Spring 支持的 <strong>Maven</strong> 版本为 3.2 以上，作为依赖管理软件，推荐使用当前最新稳定版本的 <strong>Maven</strong>。</p><p>这里给出命令行安装 <strong>Maven</strong> 的办法：</p><ul><li><p>macOS 安装：</p><pre><code class="hljs language-plaintext"><div class="MuiBox-root css-1qhimia">brew install maven </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre></li><li><p>基于 Debian 的 Linux 发行版上安装（如 Ubuntu 等）：</p><pre><code class="hljs language-plaintext"><div class="MuiBox-root css-1qhimia">apt-get install maven </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre></li><li><p>基于 Red Hat 的 Linux 发行版上安装（如 Fedora、CentOS 等）：</p></li><li><p>dnf 包管理器</p><pre><code class="hljs language-plaintext"><div class="MuiBox-root css-1qhimia">dnf install maven </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre></li><li><p>yum 包管理器</p><pre><code class="hljs language-plaintext"><div class="MuiBox-root css-1qhimia">yum install maven </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre></li></ul><p>其他安装方法，请参考 <a href="https://maven.apache.org/install.html" target="_blank" referrerpolicy="no-referrer-when-downgrade">Maven 官方文档</a>。</p><h2 id="第-4-步获取应用程序代码" style="position:relative">第 4 步：获取应用程序代码<a href="#%E7%AC%AC-4-%E6%AD%A5%E8%8E%B7%E5%8F%96%E5%BA%94%E7%94%A8%E7%A8%8B%E5%BA%8F%E4%BB%A3%E7%A0%81" aria-label="第 4 步获取应用程序代码 permalink" class="anchor after"><svg aria-hidden="true" focusable="false" height="16" version="1.1" viewbox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"/></svg></a></h2><div class="MuiBox-root css-1weqspv"><div class="MuiPaper-root MuiPaper-elevation MuiPaper-rounded MuiPaper-elevation0 MuiAlert-root MuiAlert-standardSuccess MuiAlert-standard css-9c4k42" role="alert"><div class="MuiAlert-icon css-1l54tgj"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeMedium css-vubbuv" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="AttachmentIcon"><path d="M2 12.5C2 9.46 4.46 7 7.5 7H18c2.21 0 4 1.79 4 4s-1.79 4-4 4H9.5C8.12 15 7 13.88 7 12.5S8.12 10 9.5 10H17v2H9.41c-.55 0-.55 1 0 1H18c1.1 0 2-.9 2-2s-.9-2-2-2H7.5C5.57 9 4 10.57 4 12.5S5.57 16 7.5 16H17v2H7.5C4.46 18 2 15.54 2 12.5z"/></svg></div><div class="MuiAlert-message css-1xsto0d"><div class="MuiTypography-root MuiTypography-body1 MuiTypography-gutterBottom MuiAlertTitle-root css-m00e13">小贴士</div><p>如果你希望得到一个与本示例相同依赖的空白程序，而无需示例代码，可参考<a href="#%E5%88%9B%E5%BB%BA%E7%9B%B8%E5%90%8C%E4%BE%9D%E8%B5%96%E7%A9%BA%E7%99%BD%E7%A8%8B%E5%BA%8F%E5%8F%AF%E9%80%89">创建相同依赖空白程序（可选）</a>一节。</p></div></div></div><p>请下载或克隆示例代码库 <a href="https://github.com/pingcap-inc/tidb-example-java" target="_blank" referrerpolicy="no-referrer-when-downgrade">pingcap-inc/tidb-example-java</a>，并进入到目录 <code>spring-jpa-hibernate</code> 中。</p><h2 id="第-5-步运行应用程序" style="position:relative">第 5 步：运行应用程序<a href="#%E7%AC%AC-5-%E6%AD%A5%E8%BF%90%E8%A1%8C%E5%BA%94%E7%94%A8%E7%A8%8B%E5%BA%8F" aria-label="第 5 步运行应用程序 permalink" class="anchor after"><svg aria-hidden="true" focusable="false" height="16" version="1.1" viewbox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"/></svg></a></h2><p>接下来运行应用程序代码，将会生成一个 Web 应用程序。Hibernate 将在数据库 <code>test</code> 中创建一个表 <code>player_jpa</code>。如果你向应用程序的 Restful API 发送请求，这些请求将会在 TiDB 集群上运行<a href="/zh/tidb/v6.1/dev-guide-transaction-overview">数据库事务</a>。</p><p>如果你想了解有关此应用程序的代码的详细信息，可参阅<a href="#%E5%AE%9E%E7%8E%B0%E7%BB%86%E8%8A%82">实现细节</a>部分。</p><h3 id="第-5-步第-1-部分tidb-cloud-更改参数" style="position:relative">第 5 步第 1 部分：TiDB Cloud 更改参数<a href="#%E7%AC%AC-5-%E6%AD%A5%E7%AC%AC-1-%E9%83%A8%E5%88%86tidb-cloud-%E6%9B%B4%E6%94%B9%E5%8F%82%E6%95%B0" aria-label="第 5 步第 1 部分tidb cloud 更改参数 permalink" class="anchor after"><svg aria-hidden="true" focusable="false" height="16" version="1.1" viewbox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"/></svg></a></h3><p>若你使用 TiDB Serverless 集群，更改 <code>application.yml</code>（位于 <code>src/main/resources</code> 内）关于 <code>spring.datasource.url</code>、<code>spring.datasource.username</code>、<code>spring.datasource.password</code> 的参数：</p><pre><code class="hljs language-yaml"><div class="MuiBox-root css-1qhimia"><span class="hljs-attr">spring:</span> <span class="hljs-attr">datasource:</span> <span class="hljs-attr">url:</span> <span class="hljs-string">jdbc:mysql://localhost:4000/test</span> <span class="hljs-attr">username:</span> <span class="hljs-string">root</span> <span class="hljs-comment"># password: xxx</span> <span class="hljs-attr">driver-class-name:</span> <span class="hljs-string">com.mysql.cj.jdbc.Driver</span> <span class="hljs-attr">show-sql:</span> <span class="hljs-literal">true</span> <span class="hljs-attr">database-platform:</span> <span class="hljs-string">org.hibernate.dialect.TiDBDialect</span> <span class="hljs-attr">hibernate:</span> <span class="hljs-attr">ddl-auto:</span> <span class="hljs-string">create-drop</span> </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre><p>若你设定的密码为 <code>123456</code>，而且从 TiDB Serverless 集群面板中得到的连接信息为：</p><ul><li>Endpoint: <code>xxx.tidbcloud.com</code></li><li>Port: <code>4000</code></li><li>User: <code>2aEp24QWEDLqRFs.root</code></li></ul><p>那么此处应将参数更改为：</p><pre><code class="hljs language-yaml"><div class="MuiBox-root css-1qhimia"><span class="hljs-attr">spring:</span> <span class="hljs-attr">datasource:</span> <span class="hljs-attr">url:</span> <span class="hljs-string">jdbc:mysql://xxx.tidbcloud.com:4000/test?sslMode=VERIFY_IDENTITY&amp;enabledTLSProtocols=TLSv1.2,TLSv1.3</span> <span class="hljs-attr">username:</span> <span class="hljs-string">2aEp24QWEDLqRFs.root</span> <span class="hljs-attr">password:</span> <span class="hljs-number">123456</span> <span class="hljs-attr">driver-class-name:</span> <span class="hljs-string">com.mysql.cj.jdbc.Driver</span> <span class="hljs-attr">show-sql:</span> <span class="hljs-literal">true</span> <span class="hljs-attr">database-platform:</span> <span class="hljs-string">org.hibernate.dialect.TiDBDialect</span> <span class="hljs-attr">hibernate:</span> <span class="hljs-attr">ddl-auto:</span> <span class="hljs-string">create-drop</span> </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre><h3 id="第-5-步第-2-部分运行" style="position:relative">第 5 步第 2 部分：运行<a href="#%E7%AC%AC-5-%E6%AD%A5%E7%AC%AC-2-%E9%83%A8%E5%88%86%E8%BF%90%E8%A1%8C" aria-label="第 5 步第 2 部分运行 permalink" class="anchor after"><svg aria-hidden="true" focusable="false" height="16" version="1.1" viewbox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"/></svg></a></h3><p>打开终端，进入 <code>tidb-example-java/spring-jpa-hibernate</code> 代码示例目录：</p><pre><code class="hljs language-sh"><div class="MuiBox-root css-1qhimia"><span class="hljs-built_in">cd</span> &lt;path&gt;/tidb-example-java/spring-jpa-hibernate </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre><h4 id="使用-make-构建并运行推荐" style="position:relative">使用 Make 构建并运行（推荐）<a href="#%E4%BD%BF%E7%94%A8-make-%E6%9E%84%E5%BB%BA%E5%B9%B6%E8%BF%90%E8%A1%8C%E6%8E%A8%E8%8D%90" aria-label="使用 make 构建并运行推荐 permalink" class="anchor after"><svg aria-hidden="true" focusable="false" height="16" version="1.1" viewbox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"/></svg></a></h4><pre><code class="hljs language-sh"><div class="MuiBox-root css-1qhimia">make </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre><h4 id="手动构建并运行" style="position:relative">手动构建并运行<a href="#%E6%89%8B%E5%8A%A8%E6%9E%84%E5%BB%BA%E5%B9%B6%E8%BF%90%E8%A1%8C" aria-label="手动构建并运行 permalink" class="anchor after"><svg aria-hidden="true" focusable="false" height="16" version="1.1" viewbox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"/></svg></a></h4><p>推荐你使用 Make 方式进行构建并运行，当然，若你希望手动进行构建，请依照以下步骤逐步运行，可以得到相同的结果：</p><p>清除缓存并打包：</p><pre><code class="hljs language-sh"><div class="MuiBox-root css-1qhimia">mvn clean package </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre><p>运行应用程序的 JAR 文件：</p><pre><code class="hljs language-sh"><div class="MuiBox-root css-1qhimia">java -jar target/spring-jpa-hibernate-0.0.1.jar </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre><h3 id="第-5-步第-3-部分输出" style="position:relative">第 5 步第 3 部分：输出<a href="#%E7%AC%AC-5-%E6%AD%A5%E7%AC%AC-3-%E9%83%A8%E5%88%86%E8%BE%93%E5%87%BA" aria-label="第 5 步第 3 部分输出 permalink" class="anchor after"><svg aria-hidden="true" focusable="false" height="16" version="1.1" viewbox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"/></svg></a></h3><p>输出的最后部分应如下所示：</p><pre><code class="hljs language-plaintext"><div class="MuiBox-root css-1qhimia"> . ____ _ __ _ _ /\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \ ( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \ \\/ ___)| |_)| | | | | || (_| | ) ) ) ) ' |____| .__|_| |_|_| |_\__, | / / / / =========|_|==============|___/=/_/_/_/ :: Spring Boot :: (v3.0.1) 2023-01-05T14:06:54.427+08:00 INFO 22005 --- [ main] com.pingcap.App : Starting App using Java 17.0.2 with PID 22005 (/Users/cheese/IdeaProjects/tidb-example-java/spring-jpa-hibernate/target/classes started by cheese in /Users/cheese/IdeaProjects/tidb-example-java) 2023-01-05T14:06:54.428+08:00 INFO 22005 --- [ main] com.pingcap.App : No active profile set, falling back to 1 default profile: "default" 2023-01-05T14:06:54.642+08:00 INFO 22005 --- [ main] .s.d.r.c.RepositoryConfigurationDelegate : Bootstrapping Spring Data JPA repositories in DEFAULT mode. 2023-01-05T14:06:54.662+08:00 INFO 22005 --- [ main] .s.d.r.c.RepositoryConfigurationDelegate : Finished Spring Data repository scanning in 17 ms. Found 1 JPA repository interfaces. 2023-01-05T14:06:54.830+08:00 INFO 22005 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat initialized with port(s): 8080 (http) 2023-01-05T14:06:54.833+08:00 INFO 22005 --- [ main] o.apache.catalina.core.StandardService : Starting service [Tomcat] 2023-01-05T14:06:54.833+08:00 INFO 22005 --- [ main] o.apache.catalina.core.StandardEngine : Starting Servlet engine: [Apache Tomcat/10.1.4] 2023-01-05T14:06:54.865+08:00 INFO 22005 --- [ main] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring embedded WebApplicationContext 2023-01-05T14:06:54.865+08:00 INFO 22005 --- [ main] w.s.c.ServletWebServerApplicationContext : Root WebApplicationContext: initialization completed in 421 ms 2023-01-05T14:06:54.916+08:00 INFO 22005 --- [ main] o.hibernate.jpa.internal.util.LogHelper : HHH000204: Processing PersistenceUnitInfo [name: default] 2023-01-05T14:06:54.929+08:00 INFO 22005 --- [ main] org.hibernate.Version : HHH000412: Hibernate ORM core version 6.1.6.Final 2023-01-05T14:06:54.969+08:00 WARN 22005 --- [ main] org.hibernate.orm.deprecation : HHH90000021: Encountered deprecated setting [javax.persistence.sharedCache.mode], use [jakarta.persistence.sharedCache.mode] instead 2023-01-05T14:06:55.005+08:00 INFO 22005 --- [ main] com.zaxxer.hikari.HikariDataSource : HikariPool-1 - Starting... 2023-01-05T14:06:55.074+08:00 INFO 22005 --- [ main] com.zaxxer.hikari.pool.HikariPool : HikariPool-1 - Added connection com.mysql.cj.jdbc.ConnectionImpl@5e905f2c 2023-01-05T14:06:55.075+08:00 INFO 22005 --- [ main] com.zaxxer.hikari.HikariDataSource : HikariPool-1 - Start completed. 2023-01-05T14:06:55.089+08:00 INFO 22005 --- [ main] SQL dialect : HHH000400: Using dialect: org.hibernate.dialect.TiDBDialect Hibernate: drop table if exists player_jpa Hibernate: drop sequence player_jpa_id_seq Hibernate: create sequence player_jpa_id_seq start with 1 increment by 1 Hibernate: create table player_jpa (id bigint not null, coins integer, goods integer, primary key (id)) engine=InnoDB 2023-01-05T14:06:55.332+08:00 INFO 22005 --- [ main] o.h.e.t.j.p.i.JtaPlatformInitiator : HHH000490: Using JtaPlatform implementation: [org.hibernate.engine.transaction.jta.platform.internal.NoJtaPlatform] 2023-01-05T14:06:55.335+08:00 INFO 22005 --- [ main] j.LocalContainerEntityManagerFactoryBean : Initialized JPA EntityManagerFactory for persistence unit 'default' 2023-01-05T14:06:55.579+08:00 WARN 22005 --- [ main] JpaBaseConfiguration$JpaWebConfiguration : spring.jpa.open-in-view is enabled by default. Therefore, database queries may be performed during view rendering. Explicitly configure spring.jpa.open-in-view to disable this warning 2023-01-05T14:06:55.710+08:00 INFO 22005 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat started on port(s): 8080 (http) with context path '' 2023-01-05T14:06:55.714+08:00 INFO 22005 --- [ main] com.pingcap.App : Started App in 1.432 seconds (process running for 1.654) </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre><p>输出日志中，提示应用程序在启动过程中做了什么，这里显示应用程序使用 <a href="https://tomcat.apache.org/" target="_blank" referrerpolicy="no-referrer-when-downgrade">Tomcat</a> 启动了一个 <strong>Servlet</strong>，使用 Hibernate 作为 ORM ，<a href="https://github.com/brettwooldridge/HikariCP" target="_blank" referrerpolicy="no-referrer-when-downgrade">HikariCP</a> 作为数据库连接池的实现，使用了 <code>org.hibernate.dialect.TiDBDialect</code> 作为数据库方言。启动后，Hibernate 删除并重新创建了表 <code>player_jpa</code>，及序列 <code>player_jpa_id_seq</code>。在启动的最后，监听了 8080 端口，对外提供 HTTP 服务。</p><p>如果你想了解有关此应用程序的代码的详细信息，可参阅本教程下方的<a href="#%E5%AE%9E%E7%8E%B0%E7%BB%86%E8%8A%82">实现细节</a>。</p><h2 id="第-6-步http-请求" style="position:relative">第 6 步：HTTP 请求<a href="#%E7%AC%AC-6-%E6%AD%A5http-%E8%AF%B7%E6%B1%82" aria-label="第 6 步http 请求 permalink" class="anchor after"><svg aria-hidden="true" focusable="false" height="16" version="1.1" viewbox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"/></svg></a></h2><p>在运行应用程序后，你可以通过访问根地址 <code>http://localhost:8000</code> 向后端程序发送 HTTP 请求。下面将给出一些示例请求来演示如何使用该服务。</p><ul class="simple-tab-module--tabs--tXejZ simple-tab-container"><li class="simple-tab-module--active--dcjQ4">Postman（推荐）</li><li class="">curl</li><li class="">Shell 脚本</li></ul><div class=""><ol><li><p>将配置文件 <a href="https://raw.githubusercontent.com/pingcap-inc/tidb-example-python/main/django_example/Player.postman_collection.json" target="_blank" referrerpolicy="no-referrer-when-downgrade"><code>Player.postman_collection.json</code></a> 导入 <a href="https://www.postman.com/" target="_blank" referrerpolicy="no-referrer-when-downgrade">Postman</a>。</p></li><li><p>导入后 <strong>Collections</strong> &gt; <strong>Player</strong> 如图所示：</p><p><img src="https://download.pingcap.com/images/docs-cn/develop/postman_player_import.png" alt="postman import"/></p></li><li><p>发送请求：</p><ul><li><p>增加玩家</p><p> 点击 <strong>Create</strong> 标签，点击 <strong>Send</strong> 按钮，发送 <code>POST</code> 形式的 <code>http://localhost:8000/player/</code> 请求。返回值为增加的玩家个数，预期为 1。</p><p> <img src="https://download.pingcap.com/images/docs-cn/develop/postman_player_create.png" alt="Postman-Create"/></p></li><li><p>使用 ID 获取玩家信息</p><p> 点击 <strong>GetByID</strong> 标签，点击 <strong>Send</strong> 按钮，发送 <code>GET</code> 形式的 <code>http://localhost:8000/player/1</code> 请求。返回值为 ID 为 1 的玩家信息。</p><p> <img src="https://download.pingcap.com/images/docs-cn/develop/postman_player_getbyid.png" alt="Postman-GetByID"/></p></li><li><p>使用 Limit 批量获取玩家信息</p><p> 点击 <strong>GetByLimit</strong> 标签，点击 <strong>Send</strong> 按钮，发送 <code>GET</code> 形式的 <code>http://localhost:8000/player/limit/3</code> 请求。返回值为最多 3 个玩家的信息列表。</p><p> <img src="https://download.pingcap.com/images/docs-cn/develop/postman_player_getbylimit.png" alt="Postman-GetByLimit"/></p></li><li><p>分页获取玩家信息</p><p> 点击 <strong>GetByPage</strong> 标签，点击 <strong>Send</strong> 按钮，发送 <code>GET</code> 形式的 <code>http://localhost:8080/player/page?index=0&amp;size=2</code> 请求。返回值为 index 为 0 的页，每页有 2 个玩家信息列表。此外，还包含了分页信息，如偏移量、总页数、是否排序等。</p><p> <img src="https://download.pingcap.com/images/docs-cn/develop//postman_player_getbypage.png" alt="Postman-GetByPage"/></p></li><li><p>获取玩家个数</p><p> 点击 <strong>Count</strong> 标签，点击 <strong>Send</strong> 按钮，发送 <code>GET</code> 形式的 <code>http://localhost:8000/player/count</code> 请求。返回值为玩家个数。</p><p> <img src="https://download.pingcap.com/images/docs-cn/develop/postman_player_count.png" alt="Postman-Count"/></p></li><li><p>玩家交易</p><p> 点击 <strong>Trade</strong> 标签，点击 <strong>Send</strong> 按钮，发送 <code>PUT</code> 形式的 <code>http://localhost:8000/player/trade</code> 请求。请求参数为售卖玩家 ID <code>sellID</code>、购买玩家 ID <code>buyID</code>、购买货物数量 <code>amount</code> 以及购买消耗金币数 <code>price</code>。返回值为交易是否成功。当出现售卖玩家货物不足、购买玩家金币不足或数据库错误时，交易将不成功。并且由于<a href="/zh/tidb/v6.1/dev-guide-transaction-overview">数据库事务</a>保证，不会有玩家的金币或货物丢失的情况。</p><p> <img src="https://download.pingcap.com/images/docs-cn/develop/postman_player_trade.png" alt="Postman-Trade"/></p></li></ul></li></ol></div><div class="simple-tab-module--hidden--xELDk"><p>下面使用 curl 请求服务端。</p><ul><li><p>增加玩家</p><p> 使用 <code>POST</code> 方法向 <code>/player</code> 端点发送请求来增加玩家，例如：</p><pre><code class="hljs language-sh"><div class="MuiBox-root css-1qhimia">curl --location --request POST <span class="hljs-string">'http://localhost:8080/player/'</span> --header <span class="hljs-string">'Content-Type: application/json'</span> --data-raw <span class="hljs-string">'[{"coins":100,"goods":20}]'</span> </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre><p> 这里使用 JSON 作为信息的载荷。表示需要创建一个金币数 <code>coins</code> 为 100，货物数 <code>goods</code> 为 20 的玩家。返回值为创建的玩家信息：</p><pre><code class="hljs language-json"><div class="MuiBox-root css-1qhimia"><span class="hljs-number">1</span> </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre></li><li><p>使用 ID 获取玩家信息</p><p> 使用 <code>GET</code> 方法向 <code>/player</code> 端点发送请求来获取玩家信息。此外，还需要在路径上给出玩家的 ID 参数，即 <code>/player/{id}</code>。例如，在请求 ID 为 1 的玩家时：</p><pre><code class="hljs language-sh"><div class="MuiBox-root css-1qhimia">curl --location --request GET <span class="hljs-string">'http://localhost:8080/player/1'</span> </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre><p> 返回值为 ID 为 1 的玩家的信息：</p><pre><code class="hljs language-json"><div class="MuiBox-root css-1qhimia"><span class="hljs-punctuation">{</span> <span class="hljs-attr">"coins"</span><span class="hljs-punctuation">:</span> <span class="hljs-number">200</span><span class="hljs-punctuation">,</span> <span class="hljs-attr">"goods"</span><span class="hljs-punctuation">:</span> <span class="hljs-number">10</span><span class="hljs-punctuation">,</span> <span class="hljs-attr">"id"</span><span class="hljs-punctuation">:</span> <span class="hljs-number">1</span> </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre></li><li><p>使用 Limit 批量获取玩家信息</p><p> 使用 <code>GET</code> 方法向 <code>/player/limit</code> 端点发送请求来获取玩家信息。此外，还需要在路径上给出限制查询的玩家信息的总数，即 <code>/player/limit/{limit}</code>。例如，在请求最多 3 个玩家的信息时：</p><pre><code class="hljs language-sh"><div class="MuiBox-root css-1qhimia">curl --location --request GET <span class="hljs-string">'http://localhost:8080/player/limit/3'</span> </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre><p> 返回值为玩家信息的列表：</p><pre><code class="hljs language-json"><div class="MuiBox-root css-1qhimia"><span class="hljs-punctuation">[</span> <span class="hljs-attr">"coins"</span><span class="hljs-punctuation">:</span> <span class="hljs-number">200</span><span class="hljs-punctuation">,</span> <span class="hljs-attr">"goods"</span><span class="hljs-punctuation">:</span> <span class="hljs-number">10</span><span class="hljs-punctuation">,</span> <span class="hljs-attr">"id"</span><span class="hljs-punctuation">:</span> <span class="hljs-number">1</span> <span class="hljs-attr">"coins"</span><span class="hljs-punctuation">:</span> <span class="hljs-number">0</span><span class="hljs-punctuation">,</span> <span class="hljs-attr">"goods"</span><span class="hljs-punctuation">:</span> <span class="hljs-number">30</span><span class="hljs-punctuation">,</span> <span class="hljs-attr">"id"</span><span class="hljs-punctuation">:</span> <span class="hljs-number">2</span> <span class="hljs-attr">"coins"</span><span class="hljs-punctuation">:</span> <span class="hljs-number">100</span><span class="hljs-punctuation">,</span> <span class="hljs-attr">"goods"</span><span class="hljs-punctuation">:</span> <span class="hljs-number">20</span><span class="hljs-punctuation">,</span> <span class="hljs-attr">"id"</span><span class="hljs-punctuation">:</span> <span class="hljs-number">3</span> </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre></li><li><p>分页获取玩家信息</p><p> 使用 <code>GET</code> 方法向 <code>/player/page</code> 端点发送请求来分页获取玩家信息。额外地需要使用 URL 参数，例如在请求页面序号 <code>index</code> 为 0，每页最大请求量 <code>size</code> 为 2 时：</p><pre><code class="hljs language-sh"><div class="MuiBox-root css-1qhimia">curl --location --request GET <span class="hljs-string">'http://localhost:8080/player/page?index=0&amp;size=2'</span> </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre><p> 返回值为 <code>index</code> 为 0 的页，每页有 2 个玩家信息列表。此外，还包含了分页信息，如偏移量、总页数、是否排序等。</p><pre><code class="hljs language-json"><div class="MuiBox-root css-1qhimia"><span class="hljs-punctuation">{</span> <span class="hljs-attr">"content"</span><span class="hljs-punctuation">:</span> <span class="hljs-punctuation">[</span> <span class="hljs-attr">"coins"</span><span class="hljs-punctuation">:</span> <span class="hljs-number">200</span><span class="hljs-punctuation">,</span> <span class="hljs-attr">"goods"</span><span class="hljs-punctuation">:</span> <span class="hljs-number">10</span><span class="hljs-punctuation">,</span> <span class="hljs-attr">"id"</span><span class="hljs-punctuation">:</span> <span class="hljs-number">1</span> <span class="hljs-attr">"coins"</span><span class="hljs-punctuation">:</span> <span class="hljs-number">0</span><span class="hljs-punctuation">,</span> <span class="hljs-attr">"goods"</span><span class="hljs-punctuation">:</span> <span class="hljs-number">30</span><span class="hljs-punctuation">,</span> <span class="hljs-attr">"id"</span><span class="hljs-punctuation">:</span> <span class="hljs-number">2</span> <span class="hljs-attr">"empty"</span><span class="hljs-punctuation">:</span> <span class="hljs-keyword">false</span><span class="hljs-punctuation">,</span> <span class="hljs-attr">"first"</span><span class="hljs-punctuation">:</span> <span class="hljs-keyword">true</span><span class="hljs-punctuation">,</span> <span class="hljs-attr">"last"</span><span class="hljs-punctuation">:</span> <span class="hljs-keyword">false</span><span class="hljs-punctuation">,</span> <span class="hljs-attr">"number"</span><span class="hljs-punctuation">:</span> <span class="hljs-number">0</span><span class="hljs-punctuation">,</span> <span class="hljs-attr">"numberOfElements"</span><span class="hljs-punctuation">:</span> <span class="hljs-number">2</span><span class="hljs-punctuation">,</span> <span class="hljs-attr">"pageable"</span><span class="hljs-punctuation">:</span> <span class="hljs-punctuation">{</span> <span class="hljs-attr">"offset"</span><span class="hljs-punctuation">:</span> <span class="hljs-number">0</span><span class="hljs-punctuation">,</span> <span class="hljs-attr">"pageNumber"</span><span class="hljs-punctuation">:</span> <span class="hljs-number">0</span><span class="hljs-punctuation">,</span> <span class="hljs-attr">"pageSize"</span><span class="hljs-punctuation">:</span> <span class="hljs-number">2</span><span class="hljs-punctuation">,</span> <span class="hljs-attr">"paged"</span><span class="hljs-punctuation">:</span> <span class="hljs-keyword">true</span><span class="hljs-punctuation">,</span> <span class="hljs-attr">"sort"</span><span class="hljs-punctuation">:</span> <span class="hljs-punctuation">{</span> <span class="hljs-attr">"empty"</span><span class="hljs-punctuation">:</span> <span class="hljs-keyword">true</span><span class="hljs-punctuation">,</span> <span class="hljs-attr">"sorted"</span><span class="hljs-punctuation">:</span> <span class="hljs-keyword">false</span><span class="hljs-punctuation">,</span> <span class="hljs-attr">"unsorted"</span><span class="hljs-punctuation">:</span> <span class="hljs-keyword">true</span> <span class="hljs-attr">"unpaged"</span><span class="hljs-punctuation">:</span> <span class="hljs-keyword">false</span> <span class="hljs-attr">"size"</span><span class="hljs-punctuation">:</span> <span class="hljs-number">2</span><span class="hljs-punctuation">,</span> <span class="hljs-attr">"sort"</span><span class="hljs-punctuation">:</span> <span class="hljs-punctuation">{</span> <span class="hljs-attr">"empty"</span><span class="hljs-punctuation">:</span> <span class="hljs-keyword">true</span><span class="hljs-punctuation">,</span> <span class="hljs-attr">"sorted"</span><span class="hljs-punctuation">:</span> <span class="hljs-keyword">false</span><span class="hljs-punctuation">,</span> <span class="hljs-attr">"unsorted"</span><span class="hljs-punctuation">:</span> <span class="hljs-keyword">true</span> <span class="hljs-attr">"totalElements"</span><span class="hljs-punctuation">:</span> <span class="hljs-number">4</span><span class="hljs-punctuation">,</span> <span class="hljs-attr">"totalPages"</span><span class="hljs-punctuation">:</span> <span class="hljs-number">2</span> </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre></li><li><p>获取玩家个数</p><p> 使用 <code>GET</code> 方法向 <code>/player/count</code> 端点发送请求来获取玩家个数：</p><pre><code class="hljs language-sh"><div class="MuiBox-root css-1qhimia">curl --location --request GET <span class="hljs-string">'http://localhost:8080/player/count'</span> </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre><p> 返回值为玩家个数：</p><pre><code class="hljs language-json"><div class="MuiBox-root css-1qhimia"><span class="hljs-number">4</span> </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre></li><li><p>玩家交易</p><p> 使用 <code>PUT</code> 方法向 <code>/player/trade</code> 端点发送请求来发起玩家间的交易，例如：</p><pre><code class="hljs language-sh"><div class="MuiBox-root css-1qhimia">curl --location --request PUT <span class="hljs-string">'http://localhost:8080/player/trade'</span> \ --header <span class="hljs-string">'Content-Type: application/x-www-form-urlencoded'</span> \ --data-urlencode <span class="hljs-string">'sellID=1'</span> \ --data-urlencode <span class="hljs-string">'buyID=2'</span> \ --data-urlencode <span class="hljs-string">'amount=10'</span> \ --data-urlencode <span class="hljs-string">'price=100'</span> </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre><p> 这里使用 Form Data 作为信息的载荷。表示售卖玩家 ID <code>sellID</code> 为 1、购买玩家 ID <code>buyID</code> 为 2、购买货物数量 <code>amount</code> 为 10、购买消耗金币数 <code>price</code> 为 100。</p><p> 返回值为交易是否成功：</p><pre><code class="hljs language-plaintext"><div class="MuiBox-root css-1qhimia">true </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre><p> 当出现售卖玩家货物不足、购买玩家金币不足或数据库错误时，交易将不成功。并且由于<a href="/zh/tidb/v6.1/dev-guide-transaction-overview">数据库事务</a>保证，不会有玩家的金币或货物丢失的情况。</p></li></ul></div><div class="simple-tab-module--hidden--xELDk"><p>为方便测试，你可以使用 <a href="https://github.com/pingcap-inc/tidb-example-java/blob/main/spring-jpa-hibernate/request.sh" target="_blank" referrerpolicy="no-referrer-when-downgrade"><code>request.sh</code></a> 脚本依次发送以下请求：</p><ol><li>循环创建 10 名玩家</li><li>获取 ID 为 1 的玩家信息</li><li>获取至多 3 名玩家信息列表</li><li>获取 <code>index</code> 为 0 ，<code>size</code> 为 2 的一页玩家信息</li><li>获取玩家总数</li><li>ID 为 1 的玩家作为售出方，ID 为 2 的玩家作为购买方，购买 10 个货物，耗费 100 金币</li></ol><p>使用 <code>make request</code> 或 <code>./request.sh</code> 命令运行此脚本，运行结果如下所示：</p><pre><code class="hljs language-sh"><div class="MuiBox-root css-1qhimia">&gt; make request ./request.sh loop to create 10 players: 1111111111 get player 1: {<span class="hljs-string">"id"</span>:1,<span class="hljs-string">"coins"</span>:200,<span class="hljs-string">"goods"</span>:10} get players by <span class="hljs-built_in">limit</span> 3: [{<span class="hljs-string">"id"</span>:1,<span class="hljs-string">"coins"</span>:200,<span class="hljs-string">"goods"</span>:10},{<span class="hljs-string">"id"</span>:2,<span class="hljs-string">"coins"</span>:0,<span class="hljs-string">"goods"</span>:30},{<span class="hljs-string">"id"</span>:3,<span class="hljs-string">"coins"</span>:100,<span class="hljs-string">"goods"</span>:20}] get first players: {<span class="hljs-string">"content"</span>:[{<span class="hljs-string">"id"</span>:1,<span class="hljs-string">"coins"</span>:200,<span class="hljs-string">"goods"</span>:10},{<span class="hljs-string">"id"</span>:2,<span class="hljs-string">"coins"</span>:0,<span class="hljs-string">"goods"</span>:30}],<span class="hljs-string">"pageable"</span>:{<span class="hljs-string">"sort"</span>:{<span class="hljs-string">"empty"</span>:<span class="hljs-literal">true</span>,<span class="hljs-string">"unsorted"</span>:<span class="hljs-literal">true</span>,<span class="hljs-string">"sorted"</span>:<span class="hljs-literal">false</span>},<span class="hljs-string">"offset"</span>:0,<span class="hljs-string">"pageNumber"</span>:0,<span class="hljs-string">"pageSize"</span>:2,<span class="hljs-string">"paged"</span>:<span class="hljs-literal">true</span>,<span class="hljs-string">"unpaged"</span>:<span class="hljs-literal">false</span>},<span class="hljs-string">"last"</span>:<span class="hljs-literal">false</span>,<span class="hljs-string">"totalPages"</span>:7,<span class="hljs-string">"totalElements"</span>:14,<span class="hljs-string">"first"</span>:<span class="hljs-literal">true</span>,<span class="hljs-string">"size"</span>:2,<span class="hljs-string">"number"</span>:0,<span class="hljs-string">"sort"</span>:{<span class="hljs-string">"empty"</span>:<span class="hljs-literal">true</span>,<span class="hljs-string">"unsorted"</span>:<span class="hljs-literal">true</span>,<span class="hljs-string">"sorted"</span>:<span class="hljs-literal">false</span>},<span class="hljs-string">"numberOfElements"</span>:2,<span class="hljs-string">"empty"</span>:<span class="hljs-literal">false</span>} get players count: trade by two players: <span class="hljs-literal">false</span> </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre></div><h2 id="实现细节" style="position:relative">实现细节<a href="#%E5%AE%9E%E7%8E%B0%E7%BB%86%E8%8A%82" aria-label="实现细节 permalink" class="anchor after"><svg aria-hidden="true" focusable="false" height="16" version="1.1" viewbox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"/></svg></a></h2><p>本小节介绍示例应用程序项目中的组件。</p><h3 id="总览" style="position:relative">总览<a href="#%E6%80%BB%E8%A7%88" aria-label="总览 permalink" class="anchor after"><svg aria-hidden="true" focusable="false" height="16" version="1.1" viewbox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"/></svg></a></h3><p>本示例项目的大致目录树如下所示（删除了有碍理解的部分）：</p><pre><code class="hljs language-plaintext"><div class="MuiBox-root css-1qhimia">. ├── pom.xml └── src └── main ├── java │ └── com │ └── pingcap │ ├── App.java │ ├── controller │ │ └── PlayerController.java │ ├── dao │ │ ├── PlayerBean.java │ │ └── PlayerRepository.java │ └── service │ ├── PlayerService.java │ └── impl │ └── PlayerServiceImpl.java └── resources └── application.yml </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre><p>其中：</p><ul><li><code>pom.xml</code> 内声明了项目的 Maven 配置，如依赖，打包等</li><li><code>application.yml</code> 内声明了项目的用户配置，如数据库地址、密码、使用的数据库方言等</li><li><code>App.java</code> 是项目的入口</li><li><code>controller</code> 是项目对外暴露 HTTP 接口的包</li><li><code>service</code> 是项目实现接口与逻辑的包</li><li><code>dao</code> 是项目实现与数据库连接并完成数据持久化的包</li></ul><h3 id="配置" style="position:relative">配置<a href="#%E9%85%8D%E7%BD%AE" aria-label="配置 permalink" class="anchor after"><svg aria-hidden="true" focusable="false" height="16" version="1.1" viewbox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"/></svg></a></h3><p>本节将简要介绍 <code>pom.xml</code> 文件中的 Maven 配置，及 <code>application.yml</code> 文件中的用户配置。</p><h4 id="maven-配置" style="position:relative">Maven 配置<a href="#maven-%E9%85%8D%E7%BD%AE" aria-label="maven 配置 permalink" class="anchor after"><svg aria-hidden="true" focusable="false" height="16" version="1.1" viewbox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"/></svg></a></h4><p><code>pom.xml</code> 文件为 Maven 配置，在文件内声明了项目的 Maven 依赖，打包方法，打包信息等，你可以通过<a href="#%E5%88%9B%E5%BB%BA%E7%9B%B8%E5%90%8C%E4%BE%9D%E8%B5%96%E7%A9%BA%E7%99%BD%E7%A8%8B%E5%BA%8F%E5%8F%AF%E9%80%89">创建相同依赖空白程序</a> 这一节来复刻此配置文件的生成流程，当然，也可直接复制至你的项目来使用。</p><pre><code class="hljs language-xml"><div class="MuiBox-root css-1qhimia"><span class="hljs-meta">&lt;?xml version=<span class="hljs-string">"1.0"</span> encoding=<span class="hljs-string">"UTF-8"</span>?&gt;</span> <span class="hljs-tag">&lt;<span class="hljs-name">project</span> <span class="hljs-attr">xmlns</span>=<span class="hljs-string">"http://maven.apache.org/POM/4.0.0"</span> <span class="hljs-attr">xmlns:xsi</span>=<span class="hljs-string">"http://www.w3.org/2001/XMLSchema-instance"</span> <span class="hljs-attr">xsi:schemaLocation</span>=<span class="hljs-string">"http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd"</span>&gt;</span> <span class="hljs-tag">&lt;<span class="hljs-name">modelVersion</span>&gt;</span>4.0.0<span class="hljs-tag">&lt;/<span class="hljs-name">modelVersion</span>&gt;</span> <span class="hljs-tag">&lt;<span class="hljs-name">parent</span>&gt;</span> <span class="hljs-tag">&lt;<span class="hljs-name">groupId</span>&gt;</span>org.springframework.boot<span class="hljs-tag">&lt;/<span class="hljs-name">groupId</span>&gt;</span> <span class="hljs-tag">&lt;<span class="hljs-name">artifactId</span>&gt;</span>spring-boot-starter-parent<span class="hljs-tag">&lt;/<span class="hljs-name">artifactId</span>&gt;</span> <span class="hljs-tag">&lt;<span class="hljs-name">version</span>&gt;</span>3.0.1<span class="hljs-tag">&lt;/<span class="hljs-name">version</span>&gt;</span> <span class="hljs-tag">&lt;<span class="hljs-name">relativePath</span>/&gt;</span> <span class="hljs-comment">&lt;!-- lookup parent from repository --&gt;</span> <span class="hljs-tag">&lt;/<span class="hljs-name">parent</span>&gt;</span> <span class="hljs-tag">&lt;<span class="hljs-name">groupId</span>&gt;</span>com.pingcap<span class="hljs-tag">&lt;/<span class="hljs-name">groupId</span>&gt;</span> <span class="hljs-tag">&lt;<span class="hljs-name">artifactId</span>&gt;</span>spring-jpa-hibernate<span class="hljs-tag">&lt;/<span class="hljs-name">artifactId</span>&gt;</span> <span class="hljs-tag">&lt;<span class="hljs-name">version</span>&gt;</span>0.0.1<span class="hljs-tag">&lt;/<span class="hljs-name">version</span>&gt;</span> <span class="hljs-tag">&lt;<span class="hljs-name">name</span>&gt;</span>spring-jpa-hibernate<span class="hljs-tag">&lt;/<span class="hljs-name">name</span>&gt;</span> <span class="hljs-tag">&lt;<span class="hljs-name">description</span>&gt;</span>an example for spring boot, jpa, hibernate and TiDB<span class="hljs-tag">&lt;/<span class="hljs-name">description</span>&gt;</span> <span class="hljs-tag">&lt;<span class="hljs-name">properties</span>&gt;</span> <span class="hljs-tag">&lt;<span class="hljs-name">java.version</span>&gt;</span>17<span class="hljs-tag">&lt;/<span class="hljs-name">java.version</span>&gt;</span> <span class="hljs-tag">&lt;<span class="hljs-name">maven.compiler.source</span>&gt;</span>17<span class="hljs-tag">&lt;/<span class="hljs-name">maven.compiler.source</span>&gt;</span> <span class="hljs-tag">&lt;<span class="hljs-name">maven.compiler.target</span>&gt;</span>17<span class="hljs-tag">&lt;/<span class="hljs-name">maven.compiler.target</span>&gt;</span> <span class="hljs-tag">&lt;/<span class="hljs-name">properties</span>&gt;</span> <span class="hljs-tag">&lt;<span class="hljs-name">dependencies</span>&gt;</span> <span class="hljs-tag">&lt;<span class="hljs-name">dependency</span>&gt;</span> <span class="hljs-tag">&lt;<span class="hljs-name">groupId</span>&gt;</span>org.springframework.boot<span class="hljs-tag">&lt;/<span class="hljs-name">groupId</span>&gt;</span> <span class="hljs-tag">&lt;<span class="hljs-name">artifactId</span>&gt;</span>spring-boot-starter-data-jpa<span class="hljs-tag">&lt;/<span class="hljs-name">artifactId</span>&gt;</span> <span class="hljs-tag">&lt;/<span class="hljs-name">dependency</span>&gt;</span> <span class="hljs-tag">&lt;<span class="hljs-name">dependency</span>&gt;</span> <span class="hljs-tag">&lt;<span class="hljs-name">groupId</span>&gt;</span>org.springframework.boot<span class="hljs-tag">&lt;/<span class="hljs-name">groupId</span>&gt;</span> <span class="hljs-tag">&lt;<span class="hljs-name">artifactId</span>&gt;</span>spring-boot-starter-web<span class="hljs-tag">&lt;/<span class="hljs-name">artifactId</span>&gt;</span> <span class="hljs-tag">&lt;/<span class="hljs-name">dependency</span>&gt;</span> <span class="hljs-tag">&lt;<span class="hljs-name">dependency</span>&gt;</span> <span class="hljs-tag">&lt;<span class="hljs-name">groupId</span>&gt;</span>mysql<span class="hljs-tag">&lt;/<span class="hljs-name">groupId</span>&gt;</span> <span class="hljs-tag">&lt;<span class="hljs-name">artifactId</span>&gt;</span>mysql-connector-java<span class="hljs-tag">&lt;/<span class="hljs-name">artifactId</span>&gt;</span> <span class="hljs-tag">&lt;<span class="hljs-name">scope</span>&gt;</span>runtime<span class="hljs-tag">&lt;/<span class="hljs-name">scope</span>&gt;</span> <span class="hljs-tag">&lt;/<span class="hljs-name">dependency</span>&gt;</span> <span class="hljs-tag">&lt;<span class="hljs-name">dependency</span>&gt;</span> <span class="hljs-tag">&lt;<span class="hljs-name">groupId</span>&gt;</span>org.springframework.boot<span class="hljs-tag">&lt;/<span class="hljs-name">groupId</span>&gt;</span> <span class="hljs-tag">&lt;<span class="hljs-name">artifactId</span>&gt;</span>spring-boot-starter-test<span class="hljs-tag">&lt;/<span class="hljs-name">artifactId</span>&gt;</span> <span class="hljs-tag">&lt;<span class="hljs-name">scope</span>&gt;</span>test<span class="hljs-tag">&lt;/<span class="hljs-name">scope</span>&gt;</span> <span class="hljs-tag">&lt;/<span class="hljs-name">dependency</span>&gt;</span> <span class="hljs-tag">&lt;/<span class="hljs-name">dependencies</span>&gt;</span> <span class="hljs-tag">&lt;<span class="hljs-name">build</span>&gt;</span> <span class="hljs-tag">&lt;<span class="hljs-name">plugins</span>&gt;</span> <span class="hljs-tag">&lt;<span class="hljs-name">plugin</span>&gt;</span> <span class="hljs-tag">&lt;<span class="hljs-name">groupId</span>&gt;</span>org.springframework.boot<span class="hljs-tag">&lt;/<span class="hljs-name">groupId</span>&gt;</span> <span class="hljs-tag">&lt;<span class="hljs-name">artifactId</span>&gt;</span>spring-boot-maven-plugin<span class="hljs-tag">&lt;/<span class="hljs-name">artifactId</span>&gt;</span> <span class="hljs-tag">&lt;/<span class="hljs-name">plugin</span>&gt;</span> <span class="hljs-tag">&lt;/<span class="hljs-name">plugins</span>&gt;</span> <span class="hljs-tag">&lt;/<span class="hljs-name">build</span>&gt;</span> <span class="hljs-tag">&lt;/<span class="hljs-name">project</span>&gt;</span> </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre><h4 id="用户配置" style="position:relative">用户配置<a href="#%E7%94%A8%E6%88%B7%E9%85%8D%E7%BD%AE" aria-label="用户配置 permalink" class="anchor after"><svg aria-hidden="true" focusable="false" height="16" version="1.1" viewbox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"/></svg></a></h4><p><code>application.yml</code> 此配置文件声明了用户配置，如数据库地址、密码、使用的数据库方言等。</p><pre><code class="hljs language-yaml"><div class="MuiBox-root css-1qhimia"><span class="hljs-attr">spring:</span> <span class="hljs-attr">datasource:</span> <span class="hljs-attr">url:</span> <span class="hljs-string">jdbc:mysql://localhost:4000/test</span> <span class="hljs-attr">username:</span> <span class="hljs-string">root</span> <span class="hljs-comment"># password: xxx</span> <span class="hljs-attr">driver-class-name:</span> <span class="hljs-string">com.mysql.cj.jdbc.Driver</span> <span class="hljs-attr">show-sql:</span> <span class="hljs-literal">true</span> <span class="hljs-attr">database-platform:</span> <span class="hljs-string">org.hibernate.dialect.TiDBDialect</span> <span class="hljs-attr">hibernate:</span> <span class="hljs-attr">ddl-auto:</span> <span class="hljs-string">create-drop</span> </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre><p>此配置格式为 <a href="https://yaml.org/" target="_blank" referrerpolicy="no-referrer-when-downgrade">YAML</a> 格式。其中：</p><ul><li><code>spring.datasource.url</code>：数据库连接的 URL。</li><li><code>spring.datasource.url</code>：数据库用户名。</li><li><code>spring.datasource.password</code>：数据库密码，此项为空，需注释或删除。</li><li><code>spring.datasource.driver-class-name</code>：数据库驱动，因为 TiDB 与 MySQL 兼容，则此处使用与 mysql-connector-java 适配的驱动类 <code>com.mysql.cj.jdbc.Driver</code>。</li><li><code>jpa.show-sql</code>：为 true 时将打印 JPA 运行的 SQL。</li><li><code>jpa.database-platform</code>：选用的数据库方言，此处连接了 TiDB，自然选择 TiDB 方言，注意，此方言在 6.0.0.Beta2 版本后的 Hibernate 中才可选择，请注意依赖版本。</li><li><code>jpa.hibernate.ddl-auto</code>：此处选择的 create-drop 将会在程序开始时创建表，退出时删除表。请勿在正式环境使用，但此处为示例程序，希望尽量不影响数据库数据，因此选择了此选项。</li></ul><h3 id="入口文件" style="position:relative">入口文件<a href="#%E5%85%A5%E5%8F%A3%E6%96%87%E4%BB%B6" aria-label="入口文件 permalink" class="anchor after"><svg aria-hidden="true" focusable="false" height="16" version="1.1" viewbox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"/></svg></a></h3><p>入口文件 <code>App.java</code>：</p><pre><code class="hljs language-java"><div class="MuiBox-root css-1qhimia"><span class="hljs-keyword">package</span> com.pingcap; <span class="hljs-keyword">import</span> org.springframework.boot.SpringApplication; <span class="hljs-keyword">import</span> org.springframework.boot.autoconfigure.SpringBootApplication; <span class="hljs-keyword">import</span> org.springframework.boot.context.ApplicationPidFileWriter; <span class="hljs-meta">@SpringBootApplication</span> <span class="hljs-keyword">public</span> <span class="hljs-keyword">class</span> <span class="hljs-title class_">App</span> { <span class="hljs-keyword">public</span> <span class="hljs-keyword">static</span> <span class="hljs-keyword">void</span> <span class="hljs-title function_">main</span><span class="hljs-params">(String[] args)</span> { <span class="hljs-type">SpringApplication</span> <span class="hljs-variable">springApplication</span> <span class="hljs-operator">=</span> <span class="hljs-keyword">new</span> <span class="hljs-title class_">SpringApplication</span>(App.class); springApplication.addListeners(<span class="hljs-keyword">new</span> <span class="hljs-title class_">ApplicationPidFileWriter</span>(<span class="hljs-string">"spring-jpa-hibernate.pid"</span>)); springApplication.run(args); </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre><p>入口类比较简单，首先，有一个 Spring Boot 应用程序的标准配置注解 <a href="https://docs.spring.io/spring-boot/docs/current/api/org/springframework/boot/autoconfigure/SpringBootApplication.html" target="_blank" referrerpolicy="no-referrer-when-downgrade">@SpringBootApplication</a>。有关详细信息，请参阅 Spring Boot 官方文档中的 <a href="https://docs.spring.io/spring-boot/docs/current/reference/html/using-spring-boot.html#using-boot-using-springbootapplication-annotation" target="_blank" referrerpolicy="no-referrer-when-downgrade">Using the @SpringBootApplication Annotation</a> 。随后，使用 <code>ApplicationPidFileWriter</code> 在程序启动过程中，写下一个名为 <code>spring-jpa-hibernate.pid</code> 的 PID (process identification number) 文件，可从外部使用此 PID 文件关闭此应用程序。</p><h3 id="数据库持久层" style="position:relative">数据库持久层<a href="#%E6%95%B0%E6%8D%AE%E5%BA%93%E6%8C%81%E4%B9%85%E5%B1%82" aria-label="数据库持久层 permalink" class="anchor after"><svg aria-hidden="true" focusable="false" height="16" version="1.1" viewbox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"/></svg></a></h3><p>数据库持久层，即 <code>dao</code> 包内，实现了数据对象的持久化。</p><h4 id="实体对象" style="position:relative">实体对象<a href="#%E5%AE%9E%E4%BD%93%E5%AF%B9%E8%B1%A1" aria-label="实体对象 permalink" class="anchor after"><svg aria-hidden="true" focusable="false" height="16" version="1.1" viewbox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"/></svg></a></h4><p><code>PlayerBean.java</code> 文件为实体对象，这个对象对应了数据库的一张表。</p><pre><code class="hljs language-java"><div class="MuiBox-root css-1qhimia"><span class="hljs-keyword">package</span> com.pingcap.dao; <span class="hljs-keyword">import</span> jakarta.persistence.*; * it's core entity in hibernate * <span class="hljs-doctag">@Table</span> appoint to table name <span class="hljs-meta">@Entity</span> <span class="hljs-meta">@Table(name = "player_jpa")</span> <span class="hljs-keyword">public</span> <span class="hljs-keyword">class</span> <span class="hljs-title class_">PlayerBean</span> { * <span class="hljs-doctag">@ID</span> primary key * <span class="hljs-doctag">@GeneratedValue</span> generated way. this field will use generator named "player_id" * <span class="hljs-doctag">@SequenceGenerator</span> using `sequence` feature to create a generator, * and it named "player_jpa_id_seq" in database, initial form 1 (by `initialValue` * parameter default), and every operator will increase 1 (by `allocationSize`) <span class="hljs-meta">@GeneratedValue(generator="player_id")</span> <span class="hljs-meta">@SequenceGenerator(name="player_id", sequenceName="player_jpa_id_seq", allocationSize=1)</span> <span class="hljs-keyword">private</span> Long id; * <span class="hljs-doctag">@Column</span> field <span class="hljs-meta">@Column(name = "coins")</span> <span class="hljs-keyword">private</span> Integer coins; <span class="hljs-meta">@Column(name = "goods")</span> <span class="hljs-keyword">private</span> Integer goods; <span class="hljs-keyword">public</span> Long <span class="hljs-title function_">getId</span><span class="hljs-params">()</span> { <span class="hljs-keyword">return</span> id; <span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title function_">setId</span><span class="hljs-params">(Long id)</span> { <span class="hljs-built_in">this</span>.id = id; <span class="hljs-keyword">public</span> Integer <span class="hljs-title function_">getCoins</span><span class="hljs-params">()</span> { <span class="hljs-keyword">return</span> coins; <span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title function_">setCoins</span><span class="hljs-params">(Integer coins)</span> { <span class="hljs-built_in">this</span>.coins = coins; <span class="hljs-keyword">public</span> Integer <span class="hljs-title function_">getGoods</span><span class="hljs-params">()</span> { <span class="hljs-keyword">return</span> goods; <span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title function_">setGoods</span><span class="hljs-params">(Integer goods)</span> { <span class="hljs-built_in">this</span>.goods = goods; </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre><p>这里可以看到，实体类中有很多注解，这些注解给了 Hibernate 额外的信息，用以绑定实体类和表：</p><ul><li><code>@Entity</code> 声明 <code>PlayerBean</code> 是一个实体类。</li><li><code>@Table</code> 使用注解属性 <code>name</code> 将此实体类和表 <code>player_jpa</code> 关联。</li><li><code>@Id</code> 声明此属性关联表的主键列。</li><li><code>@GeneratedValue</code> 表示自动生成该列的值，而不应手动设置，使用属性 <code>generator</code> 指定生成器的名称为 <code>player_id</code>。</li><li><code>@SequenceGenerator</code> 声明一个使用<a href="/zh/tidb/v6.1/sql-statement-create-sequence">序列</a>的生成器，使用注解属性 <code>name</code> 声明生成器的名称为 <code>player_id</code> （与 <code>@GeneratedValue</code> 中指定的名称需保持一致）。随后使用注解属性 <code>sequenceName</code> 指定数据库中序列的名称。最后，使用注解属性 <code>allocationSize</code> 声明序列的步长为 1。</li><li><code>@Column</code> 将每个私有属性声明为表 <code>player_jpa</code> 的一列，使用注解属性 <code>name</code> 确定属性对应的列名。</li></ul><h4 id="存储库" style="position:relative">存储库<a href="#%E5%AD%98%E5%82%A8%E5%BA%93" aria-label="存储库 permalink" class="anchor after"><svg aria-hidden="true" focusable="false" height="16" version="1.1" viewbox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"/></svg></a></h4><p>为了抽象数据库层，Spring 应用程序使用 <a href="https://docs.spring.io/spring-data/jpa/docs/current/reference/html/#repositories" target="_blank" referrerpolicy="no-referrer-when-downgrade">Repository</a> 接口，或者 Repository 的子接口。这个接口映射到一个数据库对象，常见的，比如会映射到一个表上。JPA 会实现一些预制的方法，比如 <a href="/zh/tidb/v6.1/sql-statement-insert">INSERT</a> ，或使用主键的 <a href="/zh/tidb/v6.1/sql-statement-select">SELECT</a> 等。</p><pre><code class="hljs language-java"><div class="MuiBox-root css-1qhimia"><span class="hljs-keyword">package</span> com.pingcap.dao; <span class="hljs-keyword">import</span> jakarta.persistence.LockModeType; <span class="hljs-keyword">import</span> org.springframework.data.domain.Page; <span class="hljs-keyword">import</span> org.springframework.data.domain.Pageable; <span class="hljs-keyword">import</span> org.springframework.data.jpa.repository.JpaRepository; <span class="hljs-keyword">import</span> org.springframework.data.jpa.repository.Lock; <span class="hljs-keyword">import</span> org.springframework.data.jpa.repository.Query; <span class="hljs-keyword">import</span> org.springframework.data.repository.query.Param; <span class="hljs-keyword">import</span> org.springframework.stereotype.Repository; <span class="hljs-keyword">import</span> java.util.List; <span class="hljs-meta">@Repository</span> <span class="hljs-keyword">public</span> <span class="hljs-keyword">interface</span> <span class="hljs-title class_">PlayerRepository</span> <span class="hljs-keyword">extends</span> <span class="hljs-title class_">JpaRepository</span>&lt;PlayerBean, Long&gt; { * use HQL to query by page * <span class="hljs-doctag">@param</span> pageable a pageable parameter required by hibernate * <span class="hljs-doctag">@return</span> player list package by page message <span class="hljs-meta">@Query(value = "SELECT player_jpa FROM PlayerBean player_jpa")</span> Page&lt;PlayerBean&gt; <span class="hljs-title function_">getPlayersByPage</span><span class="hljs-params">(Pageable pageable)</span>; * use SQL to query by limit, using named parameter * <span class="hljs-doctag">@param</span> limit sql parameter * <span class="hljs-doctag">@return</span> player list (max size by limit) <span class="hljs-meta">@Query(value = "SELECT * FROM player_jpa LIMIT :limit", nativeQuery = true)</span> List&lt;PlayerBean&gt; <span class="hljs-title function_">getPlayersByLimit</span><span class="hljs-params">(<span class="hljs-meta">@Param("limit")</span> Integer limit)</span>; * query player and add a lock for update * <span class="hljs-doctag">@param</span> id player id * <span class="hljs-doctag">@return</span> player <span class="hljs-meta">@Lock(value = LockModeType.PESSIMISTIC_WRITE)</span> <span class="hljs-meta">@Query(value = "SELECT player FROM PlayerBean player WHERE player.id = :id")</span> <span class="hljs-comment">// @Query(value = "SELECT * FROM player_jpa WHERE id = :id FOR UPDATE", nativeQuery = true)</span> PlayerBean <span class="hljs-title function_">getPlayerAndLock</span><span class="hljs-params">(<span class="hljs-meta">@Param("id")</span> Long id)</span>; </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre><p><code>PlayerRepository</code> 拓展了 Spring 用于 JPA 数据访问所使用的接口 <code>JpaRepository</code>。使用 <code>@Query</code> 注解，告诉 Hibernate 此接口如何实现查询。在此处使用了两种查询语句的语法，其中，在接口 <code>getPlayersByPage</code> 中的查询语句使用的是一种被 Hibernate 称为 <a href="https://docs.jboss.org/hibernate/orm/6.0/userguide/html_single/Hibernate_User_Guide.html#hql" target="_blank" referrerpolicy="no-referrer-when-downgrade">HQL</a> (Hibernate Query Language) 的语法。而接口 <code>getPlayersByLimit</code> 中使用的是普通的 SQL，在使用 SQL 语法时，需要将 <code>@Query</code> 的注解参数 <code>nativeQuery</code> 设置为 true。</p><p>在 <code>getPlayersByLimit</code> 注解的 SQL 中，<code>:limit</code> 在 Hibernate 中被称为<a href="https://docs.jboss.org/hibernate/orm/6.0/userguide/html_single/Hibernate_User_Guide.html#jpql-query-parameters" target="_blank" referrerpolicy="no-referrer-when-downgrade">命名参数</a>，Hibernate 将按名称自动寻找并拼接注解所在接口内的参数。你也可以使用 <code>@Param</code> 来指定与参数不同的名称用于注入。</p><p>在 <code>getPlayerAndLock</code> 中，使用了一个注解 <a href="https://docs.spring.io/spring-data/jpa/docs/current/api/org/springframework/data/jpa/repository/Lock.html" target="_blank" referrerpolicy="no-referrer-when-downgrade">@Lock</a>，此注解声明此处使用悲观锁进行锁定，如需了解更多其他锁定方式，可查看<a href="https://openjpa.apache.org/builds/2.2.2/apache-openjpa/docs/jpa_overview_em_locking.html" target="_blank" referrerpolicy="no-referrer-when-downgrade">实体锁定</a>文档。此处的 <code>@Lock</code> 仅可与 HQL 搭配使用，否则将会产生错误。当然，如果你希望直接使用 SQL 进行锁定，可直接使用注释部分的注解：</p><pre><code class="hljs language-java"><div class="MuiBox-root css-1qhimia"><span class="hljs-meta">@Query(value = "SELECT * FROM player_jpa WHERE id = :id FOR UPDATE", nativeQuery = true)</span> </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre><p>直接使用 SQL 的 <code>FOR UPDATE</code> 来增加锁。你也可通过 TiDB <a href="/zh/tidb/v6.1/sql-statement-select">SELECT 文档</a> 进行更深层次的原理学习。</p><h3 id="逻辑实现" style="position:relative">逻辑实现<a href="#%E9%80%BB%E8%BE%91%E5%AE%9E%E7%8E%B0" aria-label="逻辑实现 permalink" class="anchor after"><svg aria-hidden="true" focusable="false" height="16" version="1.1" viewbox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"/></svg></a></h3><p>逻辑实现层，即 <code>service</code> 包，内含了项目实现的接口与逻辑</p><h4 id="接口" style="position:relative">接口<a href="#%E6%8E%A5%E5%8F%A3" aria-label="接口 permalink" class="anchor after"><svg aria-hidden="true" focusable="false" height="16" version="1.1" viewbox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"/></svg></a></h4><p><code>PlayerService.java</code> 文件内定义了逻辑接口，实现接口，而不是直接编写一个类的原因，是尽量使例子贴近实际使用，体现设计的开闭原则。你也可以省略掉此接口，在依赖类中直接注入实现类，但并不推荐这样做。</p><pre><code class="hljs language-java"><div class="MuiBox-root css-1qhimia"><span class="hljs-keyword">package</span> com.pingcap.service; <span class="hljs-keyword">import</span> com.pingcap.dao.PlayerBean; <span class="hljs-keyword">import</span> org.springframework.data.domain.Page; <span class="hljs-keyword">import</span> java.util.List; <span class="hljs-keyword">public</span> <span class="hljs-keyword">interface</span> <span class="hljs-title class_">PlayerService</span> { * create players by passing in a List of PlayerBean * <span class="hljs-doctag">@param</span> players will create players list * <span class="hljs-doctag">@return</span> The number of create accounts Integer <span class="hljs-title function_">createPlayers</span><span class="hljs-params">(List&lt;PlayerBean&gt; players)</span>; * buy goods and transfer funds between one player and another in one transaction * <span class="hljs-doctag">@param</span> sellId sell player id * <span class="hljs-doctag">@param</span> buyId buy player id * <span class="hljs-doctag">@param</span> amount goods amount, if sell player has not enough goods, the trade will break * <span class="hljs-doctag">@param</span> price price should pay, if buy player has not enough coins, the trade will break <span class="hljs-keyword">void</span> <span class="hljs-title function_">buyGoods</span><span class="hljs-params">(Long sellId, Long buyId, Integer amount, Integer price)</span> <span class="hljs-keyword">throws</span> RuntimeException; * get the player info by id. * <span class="hljs-doctag">@param</span> id player id * <span class="hljs-doctag">@return</span> the player of this id PlayerBean <span class="hljs-title function_">getPlayerByID</span><span class="hljs-params">(Long id)</span>; * get a subset of players from the data store by limit. * <span class="hljs-doctag">@param</span> limit return max size * <span class="hljs-doctag">@return</span> player list List&lt;PlayerBean&gt; <span class="hljs-title function_">getPlayers</span><span class="hljs-params">(Integer limit)</span>; * get a page of players from the data store. * <span class="hljs-doctag">@param</span> index page index * <span class="hljs-doctag">@param</span> size page size * <span class="hljs-doctag">@return</span> player list Page&lt;PlayerBean&gt; <span class="hljs-title function_">getPlayersByPage</span><span class="hljs-params">(Integer index, Integer size)</span>; * count players from the data store. * <span class="hljs-doctag">@return</span> all players count Long <span class="hljs-title function_">countPlayers</span><span class="hljs-params">()</span>; </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre><h4 id="实现重要" style="position:relative">实现（重要）<a href="#%E5%AE%9E%E7%8E%B0%E9%87%8D%E8%A6%81" aria-label="实现重要 permalink" class="anchor after"><svg aria-hidden="true" focusable="false" height="16" version="1.1" viewbox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"/></svg></a></h4><p><code>PlayerService.java</code> 文件内实现了 <code>PlayerService</code> 接口，所有数据操作逻辑都编写在这里。</p><pre><code class="hljs language-java"><div class="MuiBox-root css-1qhimia"><span class="hljs-keyword">package</span> com.pingcap.service.impl; <span class="hljs-keyword">import</span> com.pingcap.dao.PlayerBean; <span class="hljs-keyword">import</span> com.pingcap.dao.PlayerRepository; <span class="hljs-keyword">import</span> com.pingcap.service.PlayerService; <span class="hljs-keyword">import</span> jakarta.transaction.Transactional; <span class="hljs-keyword">import</span> org.springframework.beans.factory.annotation.Autowired; <span class="hljs-keyword">import</span> org.springframework.data.domain.Page; <span class="hljs-keyword">import</span> org.springframework.data.domain.PageRequest; <span class="hljs-keyword">import</span> org.springframework.stereotype.Service; <span class="hljs-keyword">import</span> java.util.List; * PlayerServiceImpl implements PlayerService interface * <span class="hljs-doctag">@Transactional</span> it means every method in this class, will package by a pair of * transaction.begin() and transaction.commit(). and it will be call * transaction.rollback() when method throw an exception <span class="hljs-meta">@Service</span> <span class="hljs-meta">@Transactional</span> <span class="hljs-keyword">public</span> <span class="hljs-keyword">class</span> <span class="hljs-title class_">PlayerServiceImpl</span> <span class="hljs-keyword">implements</span> <span class="hljs-title class_">PlayerService</span> { <span class="hljs-meta">@Autowired</span> <span class="hljs-keyword">private</span> PlayerRepository playerRepository; <span class="hljs-meta">@Override</span> <span class="hljs-keyword">public</span> Integer <span class="hljs-title function_">createPlayers</span><span class="hljs-params">(List&lt;PlayerBean&gt; players)</span> { <span class="hljs-keyword">return</span> playerRepository.saveAll(players).size(); <span class="hljs-meta">@Override</span> <span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title function_">buyGoods</span><span class="hljs-params">(Long sellId, Long buyId, Integer amount, Integer price)</span> <span class="hljs-keyword">throws</span> RuntimeException { <span class="hljs-type">PlayerBean</span> <span class="hljs-variable">buyPlayer</span> <span class="hljs-operator">=</span> playerRepository.getPlayerAndLock(buyId); <span class="hljs-type">PlayerBean</span> <span class="hljs-variable">sellPlayer</span> <span class="hljs-operator">=</span> playerRepository.getPlayerAndLock(sellId); <span class="hljs-keyword">if</span> (buyPlayer == <span class="hljs-literal">null</span> || sellPlayer == <span class="hljs-literal">null</span>) { <span class="hljs-keyword">throw</span> <span class="hljs-keyword">new</span> <span class="hljs-title class_">RuntimeException</span>(<span class="hljs-string">"sell or buy player not exist"</span>); <span class="hljs-keyword">if</span> (buyPlayer.getCoins() &lt; price || sellPlayer.getGoods() &lt; amount) { <span class="hljs-keyword">throw</span> <span class="hljs-keyword">new</span> <span class="hljs-title class_">RuntimeException</span>(<span class="hljs-string">"coins or goods not enough, rollback"</span>); buyPlayer.setGoods(buyPlayer.getGoods() + amount); buyPlayer.setCoins(buyPlayer.getCoins() - price); playerRepository.save(buyPlayer); sellPlayer.setGoods(sellPlayer.getGoods() - amount); sellPlayer.setCoins(sellPlayer.getCoins() + price); playerRepository.save(sellPlayer); <span class="hljs-meta">@Override</span> <span class="hljs-keyword">public</span> PlayerBean <span class="hljs-title function_">getPlayerByID</span><span class="hljs-params">(Long id)</span> { <span class="hljs-keyword">return</span> playerRepository.findById(id).orElse(<span class="hljs-literal">null</span>); <span class="hljs-meta">@Override</span> <span class="hljs-keyword">public</span> List&lt;PlayerBean&gt; <span class="hljs-title function_">getPlayers</span><span class="hljs-params">(Integer limit)</span> { <span class="hljs-keyword">return</span> playerRepository.getPlayersByLimit(limit); <span class="hljs-meta">@Override</span> <span class="hljs-keyword">public</span> Page&lt;PlayerBean&gt; <span class="hljs-title function_">getPlayersByPage</span><span class="hljs-params">(Integer index, Integer size)</span> { <span class="hljs-keyword">return</span> playerRepository.getPlayersByPage(PageRequest.of(index, size)); <span class="hljs-meta">@Override</span> <span class="hljs-keyword">public</span> Long <span class="hljs-title function_">countPlayers</span><span class="hljs-params">()</span> { <span class="hljs-keyword">return</span> playerRepository.count(); </div><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-1rmx1rm" tabindex="0" type="button" aria-label="Toggle code wrap"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="WrapTextIcon"><path d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3 3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"/></svg></button><button class="MuiButtonBase-root MuiIconButton-root MuiIconButton-sizeSmall css-fxo539" tabindex="0" type="button" aria-label="copy"><svg class="MuiSvgIcon-root MuiSvgIcon-fontSizeInherit css-1cw4hi4" focusable="false" aria-hidden="true" viewbox="0 0 24 24" data-testid="ContentCopyIcon"><path d="M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z"/></svg></button></code></pre><p>这里使用了 <code>@Service</code> 这个注解，声明此对象的生命周期交由 Spring 管理。</p><p>注意，除了有 <code>@Service</code> 注解之外，PlayerServiceImpl 实现类还有一个 <a href="https://docs.spring.io/spring-framework/docs/current/reference/html/data-access.html#transaction-declarative-annotations" target="_blank" referrerpolicy="no-referrer-when-downgrade">@Transactional</a> 注解。当在应用程序中启用事务管理时 (可使用 <a href="https://docs.spring.io/spring-framework/docs/current/javadoc-api/org/springframework/transaction/annotation/EnableTransactionManagement.html" target="_blank" referrerpolicy="no-referrer-when-downgrade">@EnableTransactionManagement</a> 打开，但 Spring Boot 默认开启，无需再次手动配置)，Spring 会自动将所有带有 <code>@Transactional</code> 注释的对象包装在一个代理中，使用该代理对对象的调用进行处理。</p><p>你可以简单的认为，代理在带有 <code>@Transactional</code> 注释的对象内的函数调用时：在函数顶部将使用 <code>transaction.begin()</code> 开启事务，函数返回后，调用 <code>transaction.commit()</code> 进行事务提交，而出现任何运行时错误时，代理将会调用 <code>transaction.rollback()</code> 来回滚。</p><p>你可参阅<a href="/zh/tidb/v6.1/dev-guide-transaction-overview">数据库事务</a>来获取更多有关事务的信息，或者阅读 Spring 官网中的文章 <a href="https://docs.spring.io/spring-framework/docs/current/reference/html/data-access.html#tx-decl-explained" target="_blank" referrerpolicy="no-referrer-when-downgrade">理解 Spring 框架的声明式事务实现</a>。</p><p>整个实现类中，<code>buyGoods</code> 函数需重点关注，其在不符合逻辑时将抛出异常，引导 Hibernate 进行事务回滚，防止出现错误数据。</p><h3 id="外部接口" style="position:relative">外部接口<a href="#%E5%A4%96%E9%83%A8%E6%8E%A5%E5%8F%A3" aria-label="外部接口 permalink" class="anchor after"><svg aria-hidden="true" focusable="false" height="16" version="1.1" viewbox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"/></svg></a></h3><p><code>controller</code> 包对外暴露 HTTP 接口，可以通过 <a href="https://www.redhat.com/en/topics/api/what-is-a-rest-api#" target="_blank" referrerpolicy="no-referrer-when-downgrade">REST API</a> 来访问服务。</p><pre><code class="hljs language-java"><div class="MuiBox-root css-1qhimia"><span class="hljs-keyword">package</span> com.pingcap.controller; <span class="hljs-keyword">import</span> com.pingcap.dao.PlayerBean; <span class="hljs-keyword">import</span> com.pingcap.service.PlayerService; <span class="hljs-keyword">import</span> org.springframework.beans.factory.annotation.Autowired; <span class="hljs-keyword">import</span> org.springframework.data.domain.Page; <span class="hljs-keyword">import</span> org.springframework.lang.NonNull; <span class="hljs-keyword">import</span> org.springframework.web.bind.annotation.*; <span class="hljs-keyword">import</span> java.util.List; <span class="hljs-meta">@RestController</span> <span class="hljs-meta">@RequestMapping("/player")</span> <span class="hljs-keyword">public</span> <span class="hljs-keyword">class</span> <span class="hljs-title class_">PlayerController</span> { <span class="hljs-meta">@Autowired</span> <span class="hljs-keyword">private</span> PlayerService playerService; <span class="hljs-meta">@PostMapping</span> <span class="hljs-keyword">public</span> Integer <span class="hljs-title function_">createPlayer</span><span class="hljs-params">(<span class="hljs-meta">@RequestBody</span> <span class="hljs-meta">@NonNull</span> List&lt;PlayerBean&gt; playerList)</span> { <span class="hljs-keyword">return</span> playerService.createPlayers(playerList); <span class="hljs-meta">@GetMapping("/{id}")</span> <span class="hljs-keyword">public</span> PlayerBean <span class="hljs-title function_">getPlayerByID</span><span class="hljs-params">(<span class="hljs-meta">@PathVariable</span> Long id)</span> { <span class="hljs-keyword">return</span> playerService.getPlayerByID(id); <span class="hljs-meta">@GetMapping("/limit/{limit_size}")</span> <span class="hljs-keyword">public</span> List&lt;PlayerBean&gt; <span class="hljs-title function_">getPlayerByLimit</span><span class="hljs-params">(<span class="hljs-meta">@PathVariable("limit_size")</span> Integer limit)</span> { <span class="hljs-keyword">return</span> playerService.getPlayers(limit); <span class="hljs-meta">@GetMapping("/page")</span> <span class="hljs-keyword">public</span> Page&lt;PlayerBean&gt; <span class="hljs-title function_">getPlayerByPage</span><span class="hljs-params">(<span class="hljs-meta">@RequestParam</span> Integer index, <span class="hljs-meta">@RequestParam("size")</span> Integer size)</span> { <span class="hljs-keyword">return</span> playerService.getPlayersByPage(index, size); <span class="hljs-meta">@GetMapping("/count")</span> <span class="hljs-keyword">public</span> Long <span class="hljs-title function_">getPlayersCount</span><span class="hljs-params">()</span> { <span class="hljs-keyword">return</span> playerService.countPlayers(); <span class="hljs-meta">@PutMapping("/trade")</span> <span class="hljs-keyword">public</span> Boolean <span class="hljs-title function_">trade</span><span class="hljs-params">(<span class="hljs-meta">@RequestParam</span> Long sellID, <span class="hljs-meta">@RequestParam</span> Long buyID, <span class="hljs-meta">@RequestParam</span> Integer amount, <span class="hljs-meta">@RequestParam</span> Integer price)</span> { <span class="hljs-keyword">try</span> { playerService.buyGoods(sellID, buyID, amount, price); } <span class="hljs-keyword">catch</span> (RuntimeException e) { <span class="hljs-keyword">return</span> <span class="hljs-literal">false</span>;