如何以嵌套json格式返回DB数据？

Question

我已经以json格式返回数据，但是我想将其转换为嵌套的json格式数据。

我的代码写在春天，使得以下

@GET 
@Path("/findall") 
public List<UserRole> getAll() { 

      return userroleservice.findAll(); 
} 

该程序返回以下输出

[{"roleId":1,"roleName":"system Admin","createUser":"1","createActive":"N"},{"roleId":2,"roleName":"admin","createUser":"1","createActive":"Y"},{"roleId":3,"roleName":"system Admin","createUser":"1","createActive":"Y"}] 

如何将其转换为嵌套的JSON格式一样

[{ "id": 1, "data": "Category", "attr": { "id": "1", "selected": false }, "children": 
       [ 
        { "id": 2, "data": "SubCategory1", "attr": { "id": "2",  "selected": false }, "children": 
          [{ "id": 4, "data": "Item1", "attr": { "id": "4", "selected": false }, "children": [] }, 
          { "id": 5, "data": "Item2", "attr": { "id": "5", "selected": false }, "children": [] }, 
          { "id": 6, "data": "Item3", "attr": { "id": "6", "selected": false }, "children": [] } 
          ] 
        }, 

        { "id": 3, "data": "SubCategory2", "attr": { "id": "3", "selected": false }, "children": 
          [{ "id": 7, "data": "Item4", "attr": { "id": "7", "selected": false }, "children": [] }, 
           { "id": 8, "data": "Item5", "attr": { "id": "8", "selected": false }, "children": [] }, 
           { "id": 9, "data": "Item6", "attr": { "id": "9", "selected": false }, "children": [] } 
          ] 
        } 
       ] 
}]; 

或者如何以嵌套json格式返回DB数据？

请任何人帮忙。

Answer 1

1. 创建一个与您想拥有的JSON格式相对应的新类。使用JSON TO POJO链接生成所需的java类
2. 完成POJO生成后，编写一个将DB对象转换为新POJO对象的翻译器。
3. 通过相同的下一层