list转换为树结构--递归

public static   JSONArray treeMenuList(List<Map<String, Object>> menuList, Object parentId) {  	
	       JSONArray childMenu = new JSONArray();  
	       for (Object object : menuList) {  
	           JSONObject jsonMenu = JSONObject.fromObject(object);  
	           Object menuId = jsonMenu.get("子");  
	           Object pid = jsonMenu.get("父");
	           if (parentId.toString().equals(pid.toString())) {  
	               JSONArray c_node = treeMenuList(menuList, menuId);  
	               jsonMenu.put("child", c_node);  
	               childMenu.add(jsonMenu);  
	           }  
	       }  
	       return childMenu;  
	   } 

 传入根节点，返回树形结构