2020-09-17 16:21:33

有一个 List<RecipeCalendar> ,数据库中查询出来的列表,需要聚合并转换类型为一个map:

Map<String, Map<Integer, RecipeCalendarInfoVO>>

这里的key是日期( RecipeCalendar.recipeDate格式yyyy-MM-dd ),value是当日(早,中,晚)的食谱区间map;

食谱区间map( Map<Integer, RecipeCalendarInfoVO> )的key是10.早餐 20.中餐 30.晚餐(RecipeCalendar.intervalType), value是实际的食谱详细信息( RecipeCalendarInfoVO(内容参考类信息) )

RecipeCalendar类(省略get,set方法):

@Data
public class RecipeCalendar extends Model<RecipeCalendar> {
    private static final long serialVersionUID = 1L;
     * 食谱日历 主键
    @TableId(value = "id", type = IdType.AUTO)
    private Long id;
     * 患者唯一编号
    private Long patientFileId;
     * 租户ID
    @TableField(fill = FieldFill.INSERT)
    private Long tenantId;
     * 员工id
    private Long employeeId;
     * 员工姓名
    private String employeeName;
     * 食谱ID
    private Long recipeId;
     * 日期区间 10.早餐 20.中餐 30.晚餐
    private Integer intervalType;
     * 食谱日历日期 格式 YYYY-MM-DD,范围 1000-01-01/9999-12-31
    private Date recipeDate;
     * 食谱名称
    private String recipeName;
     * 食谱热量(kcal)
    private Integer calories;
RecipeCalendarInfoVO类(省略get,set方法): 
 
@Data
public class RecipeCalendarInfoVO{
	@ApiModelProperty("食谱总热量(sum(RecipeCalendar.calories))")
	private Integer calories;
	@ApiModelProperty("食谱列表")
	private List<RecipeCalendar> recipeCalendarList;
聚合并转换类型(使用Collectors.groupingBy和Collectors.collectingAndThen):
 
// 集合不为空
List<RecipeCalendar> list;
SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd");
// 数据聚合转换
Map<String, Map<Integer, RecipeCalendarInfoVO>> recipeCalendarDateMap = list.stream()
		.collect(
			// 根据日期聚合
			Collectors.groupingBy(recipeCalendar -> simpleDateFormat.format(recipeCalendar.getRecipeDate()),
				// 保持顺序,用LinkedHashMap::new
				LinkedHashMap::new,
				// 根据日期区间(早,中,晚)聚合第二层
				Collectors.groupingBy(RecipeCalendar::getIntervalType,
					// 保持顺序,用LinkedHashMap::new
					LinkedHashMap::new,
					// 处理内层list 转换为 RecipeCalendarInfoVO
					Collectors.collectingAndThen(Collectors.toList(), recipeCalendars -> {
						RecipeCalendarInfoVO recipeCalendarInfoVO = new RecipeCalendarInfoVO();
						recipeCalendarInfoVO.setCalories(recipeCalendars.stream().mapToInt(recipeCalendar -> recipeCalendar.getCalories() == null ? 0 : recipeCalendar.getCalories()).sum());
						recipeCalendarInfoVO.setRecipeCalendarList(recipeCalendars);
						return recipeCalendarInfoVO;
		))));
return recipeCalendarDateMap;