【Java后端封装数据】常见后端封装数据的格式，用于返回给前端使用（109）

数据格式一：包装 List Map 返回，常用于数据展示；

// Controller：public Result selectRegConfig(@RequestBody String param) {try {Map<String, Object> paramMap = JsonUtils.readValue(param, Map.class);return Result.success().result(xxxListService.selectRegConfig(paramMap));} catch (Exception e) {log.error("QuestionListController selectRegConfig is error===:" + e.getMessage(), e);return Result.failure("查询失败");}}// Service:做了分页展示，所以使用PageInfo<Map<String, Object>>接收PageInfo<Map<String, Object>> selectRegConfig(Map<String, Object> paramMap);// ServiceImpl@Overridepublic PageInfo<Map<String, Object>> selectRegConfig(Map<String, Object> paramMap) {List<Map<String, Object>> list = xxxListMapper.selectRegConfig(paramMap);PageInfo<Map<String, Object>> result = new PageInfo<>(list);return result;}

数据格式二：包装 对象返回；通过封装POJO对象返回数据；

// POJO：@Datapublic class DataCount {private String total;  // 总数private String closed;  // 已关闭}// Controller：public Result getDeclaratData(HttpServletRequest request,@RequestBody String param) {try {Map<String, Object> paramMap = JsonUtils.readValue(param, Map.class);return Result.success().result(xxxListService.getDeclaratData(request,paramMap));} catch (Exception e) {log.error("QuestionListController getDeclaratData is error===:" + e.getMessage(), e);return Result.failure("查询失败");}}// Service:DataCount getDeclaratData (HttpServletRequest request, Map<String, Object> paramMap);// ServiceImpl@Overridepublic DataCount  getDeclaratData(HttpServletRequest request, Map<String, Object> paramMap) {DataCount data = new DataCount();int total = 0;int closed = 0;data.setTotal(String.valueOf(total));data.setClosed(String.valueOf(closed));return data;}

数据格式三：包装 Map返回；

// Controller：public Result getRevealData(HttpServletRequest request,@RequestBody String param) {try {Map<String, Object> paramMap = JsonUtils.readValue(param, Map.class);return Result.success().result(xxxListService.getRevealData(request,paramMap));} catch (Exception e) {log.error("QuestionListController getRevealData is error===:" + e.getMessage(), e);return Result.failure("失败");}}// Service:Map<String, Object> getRevealData (HttpServletRequest request,Map<String, Object> paramMap);// ServiceImpl@Overridepublic Map<String, Object> getRevealData (HttpServletRequest request, Map<String, Object> paramMap) {Map<String,Object> map = new HashMap<>();int A = 0;  int B = 0; map.put("A",A);map.put("B",B);return map;}

数据格式四：对象，Map，List互相嵌套（随意嵌套封装返回）；
如：
1.对象里面嵌套对象，嵌套List等；
2.Map里面嵌套map，嵌套List等；
3.对象和Map互相嵌套等；
返回可以是：List Map ，对象，Map；

总结：包装对象和包装Map从结果上来看是一样的，就看自己使用习惯！