public class ApiResponse<T> {
    private int status;
    private String message;
    private T data;

    public ApiResponse(int status, String message, T data) {
        this.status = status;
        this.message = message;
        this.data = data;
    }

    // Getters and Setters
}

@ControllerAdvice
public class GlobalResponseBodyAdvice implements ResponseBodyAdvice<Object> {

    @Override
    public boolean supports(MethodParameter returnType, Class converterType) {
        // 判斷是否需要處理響應(yīng)體
        return true;
    }

    @Override
    public Object beforeBodyWrite(Object body, MethodParameter returnType, MediaType selectedContentType,
                                  Class selectedConverterType, ServerHttpRequest request, ServerHttpResponse response) {
        // 包裝響應(yīng)體
        if (body instanceof ApiResponse) {
            return body;
        }
        return new ApiResponse<>(HttpStatus.OK.value(), "Success", body);
    }
}

@ControllerAdvice //添加完此注解后，此類隨著springboot項(xiàng)目的啟動(dòng)而啟動(dòng)，并且會(huì)監(jiān)控controller的異常.監(jiān)聽項(xiàng)目中所有的異常
@ResponseBody
public class MyExceptionAdvice {

    //這里的一場(chǎng)都是意外異常，并不是業(yè)務(wù)異常，業(yè)務(wù)異常后端controller會(huì)處理返回給前端.業(yè)務(wù)異常會(huì)和前端溝通好已規(guī)定的狀態(tài)碼返回。
    @ExceptionHandler(NullPointerException.class)
    public ApiResponse<String> doNullPointerException(NullPointerException e){
        ApiResponse<String> apiResponse = new ApiResponse<>(HttpStatus.INTERNAL_SERVER_ERROR.value(), e.getMessage(), null);
        return apiResponse;
    }

    // 默認(rèn)的異常處理，當(dāng)有有異常出現(xiàn)的時(shí)候，會(huì)先匹配子類的異常，當(dāng)所有的異常都沒有匹配的時(shí)候就會(huì)走這一條默認(rèn)的一場(chǎng)路線業(yè)務(wù)。
    @ExceptionHandler(Exception.class)
    public ApiResponse<String> doException(Exception e){
        ApiResponse<String> apiResponse = new ApiResponse<>(HttpStatus.INTERNAL_SERVER_ERROR.value(), e.getMessage(), null);
        return apiResponse;
    }
}

@RestController
@RequestMapping("/user")
public class UserController {

    @RequestMapping("login")
    public String login(){
        Object obj = null;
        System.out.println(obj.hashCode());
        return  "這里是login";
    }

    @GetMapping("/data")
    public User getUserData() {
        // 這個(gè)方法會(huì)返回一個(gè)User對(duì)象
        User user = new User();
        user.setId(1);
        user.setName("張三");
        user.setEmail("zhangsan@example.com");
        return user;
    }

    @GetMapping("/success")
    public Integer getSuccessMessage() {
        // 這個(gè)方法會(huì)返回一個(gè)簡(jiǎn)單的字符串
        return 123456;
    }
}