JAVA 转换 树结构数据

第二步：用到了工具内的JSONPath

JSONPath使用教程

    
    public static  List tree(Object obj, String parentCodeFieldName, String parentCode, String currentCodeFieldName, String childrenFiledName, Class c) {
 long t1 = System.currentTimeMillis();
 String jsonStr = JSON.toJSONString(obj);
 log.debug("树转换开始 >>>>>>>>>>>>>>>> {}", JSON.toJSONString(obj));
 //获取第一层级的数据
 JSonArray jsonArray = (JSONArray) JSONPath.read(jsonStr, "$[" + parentCodeFieldName + "=" + parentCode + "]");
 if (CollectionUtils.isEmpty(jsonArray)) {
     //为空的话直接返回空集合
     return Lists.newArrayList();
 }
 for (int i = 0; i < jsonArray.size(); i++) {
     JSonObject jsonObject = jsonArray.getJSONObject(i);
     String code = jsonObject.getString(currentCodeFieldName);
     treeChildren(jsonStr, jsonObject, parentCodeFieldName, code, currentCodeFieldName, childrenFiledName);
 }
 List list = JSONArray.parseArray(jsonArray.toString(), c);
 log.debug("树转换结束, 转换时间: {} ms . >>>>>>>>>>>>>>>> {}", (System.currentTimeMillis() - t1), JSON.toJSONString(list));
 return list;
    }

    private static void treeChildren(String jsonStr, JSonObject currentJsonObj, String parentCodeFieldName, String parentCode, String currentCodeFieldName, String childrenFiledName) {
 JSonArray jsonArray = (JSONArray) JSONPath.read(jsonStr, "$[" + parentCodeFieldName + "=" + parentCode + "]");
 if (CollectionUtils.isEmpty(jsonArray)) {
     return;
 }
 currentJsonObj.put(childrenFiledName, jsonArray);
 for (int i = 0; i < jsonArray.size(); i++) {
     JSonObject jsonObject = jsonArray.getJSONObject(i);
     String code = jsonObject.getString(currentCodeFieldName);
     treeChildren(jsonStr, jsonObject, parentCodeFieldName, code, currentCodeFieldName, childrenFiledName);
 }
    }