jsonpath的简单使用__jsonpath

过滤器是用于筛选数组的逻辑表达式。一个典型的过滤器将是[?(@.age > 18)]，其中@表示正在处理的当前项目。可以使用逻辑运算符&&和||创建更复杂的过滤器。字符串文字必须用单引号或双引号括起来([?(@.color == ‘blue’)] 或者 [?(@.color == “blue”)]).

left等于right（注意1不等于’1’）匹配正则表达式[?(@.name =~ /foo.*?/i)] 左边存在于右边 [?(@.size in [‘S’, ‘M’])] 左边不存在于右边（数组或字符串）长度


    empty

（数组或字符串）为空 "store": { "book": [ "category": "reference", "author": "Nigel Rees", "title": "Sayings of the Century", "price": 8.95 "category": "fiction", "author": "Evelyn Waugh", "title": "Sword of Honour", "price": 12.99 "category": "fiction", "author": "Herman Melville", "title": "Moby Dick", "isbn": "0-553-21311-3", "price": 8.99 "category": "fiction", "author": "J. R. R. Tolkien", "title": "The Lord of the Rings", "isbn": "0-395-19395-8", "price": 22.99 "bicycle": { "color": "red", "price": 19.95 "expensive": 10

JsonPath (点击链接测试)
`$.store.book[*\].author`	获取json中store下book下的所有author值
`$..author`	获取所有json中所有author的值
`$.store.*`	所有的东西，书籍和自行车
`$.store..price`	获取json中store下所有price的值
`$..book[2\]`	获取json中book数组的第3个值
`$..book[-2\]`	倒数的第二本书
`$..book[0,1\]`
`$..book[:2\]`	从索引0（包括）到索引2（排除）的所有图书
`$..book[1:2\]`	从索引1（包括）到索引2（排除）的所有图书
`$..book[-2:\]`	获取json中book数组的最后两个值
`$..book[2:\]`	获取json中book数组的第3个到最后一个的区间值
`$..book[?(@.isbn)\]`	获取json中book数组中包含isbn的所有值
[ `$.store.book[?(@.price < 10)\]` ](http://jsonpath.herokuapp.com/?path=$.store.book[?(@.price < 10)])	获取json中book数组中price<10的所有值
[ `$..book[?(@.price <= $['expensive'\])]` ](http://jsonpath.herokuapp.com/?path=$…book[?(@.price <= $[‘expensive’])])	获取json中book数组中price<=expensive的所有值
[ `$..book[?(@.author =~ /.REES/i)\]` ](http://jsonpath.herokuapp.com/?path=$…book[?(@.author =~ /.REES/i)])	获取json中book数组中的作者以REES结尾的所有值（REES不区分大小写）	逐层列出json中的所有值，层级由外到内
`$..book.length()`	获取json中book数组的长度

String json = "{...}";
String str = JsonPath.read(document, "$.store.book[0].author");