=============
后端_结果封装
=============

将后端返回给前端的数据进行封装，其中包含：

- 响应代码
  - 200表示成功，其它表示各种错误
- 结果消息
  - 操作成功或错误描述
- 结果数据
  - 查询结果

/src/main/java/com/weihome/barblog/common/Result.java：

/**
 * 响应结果类
 */
@Data
@AllArgsConstructor
public class Result implements Serializable {
    private int    code;    // 响应代码
    private String message; // 结果消息
    private Object data;    // 结果数据

    public static Result ok(Object data) {
        return new Result(200, "操作成功", data);
    }

    public static Result error(String message) {
        return new Result(400, message, null);
    }

    public static Result error(int code, String message) {
        return new Result(code, message, null);
    }
}

/src/main/java/com/weihome/barblog/controller/UserController.java：

@RestController
@RequestMapping("/user")
public class UserController {
    @Autowired
    private UserService userService;

    @GetMapping("/index")
    public Result index() {
        return Result.ok(userService.getById(1L));
    }
}

执行BarblogApplication.main()...

http://localhost:8081/user/index

{
    "code": 200,
    "message": "操作成功",
    "data": {
        "id": 1,
        "username": "bear",
        "avatar": "bear.png",
        "email": "johnmin74@hotmail.com",
        "password": "96e79218965eb72c92a549dd5a330112",
        "status": 0,
        "created": "2022-03-22T12:00:00",
        "lastLogin": null
    }
}