还再在Controller接口写统一返回的JSON结构？快来试试@ControllerAdvice注解

众所周知目前前后端交互基本都采用标准的JSON结构{"code": 200, "message": "成功", "data": null}
不认识@ControllerAdvice注解之前接口是这样返回的

    @GetMapping("/")
    public BaseResponse test() {
        String testMsg = testService.getTestMsg();
        return BaseResponse.ok(testMsg);
    }
    
    @GetMapping("/findUser/{id}")
    public BaseResponse findUserById(@PathVariable("id") Long userId) {
        User user = testService.findUserById(userId);
        return BaseResponse.ok(user);
    }

BaseResponse为统一返回的对象

@Data
@EqualsAndHashCode
@NoArgsConstructor
public class BaseResponse {

    /**
     * 响应码
     */
    private Integer code;

    /**
     * 响应消息
     */
    private String msg;

    /**
     * 响应数据
     */
    private T data;

    public BaseResponse(Integer status, String msg, T data) {
        this.code = status;
        this.msg = msg;
        this.data = data;
    }


    @NonNull
    public static  BaseResponse ok(@Nullable String msg, @Nullable T data) {
        return new BaseResponse<>(HttpStatus.OK.value(), msg, data);
    }

    @NonNull
    public static  BaseResponse ok(@Nullable String msg) {
        return ok(msg, null);
    }


    public static  BaseResponse ok(@Nullable T data) {
        return new BaseResponse<>(HttpStatus.OK.value(), HttpStatus.OK.getReasonPhrase(), data);
    }
}

认识@ControllerAdvice注解之后接口是这样返回的

    @GetMapping("/")
    public String test() {
        String testMsg = testService.getTestMsg();
        return testMsg;
    }

    @GetMapping("/findUser/{id}")
    public User findUserById(@PathVariable("id") Long userId) {
        User user = testService.findUserById(userId);
        return user;
    }

使用了@ControllerAdvice 注解对Controller层的所有接口做拦截，然后使用BaseResponse进行统一的封装，这样就不必再在每个Controller接口里都去使用BaseResponse进行封装了

@ControllerAdvice("com.test.controller")
public class CommonResultControllerAdvice implements ResponseBodyAdvice