Question

Spring Boot似乎具有处理某些异常的默认行为。我有休息控制器。如果我在HttpRequestMethodNotSupportedException带注释的rest控制器中不处理@ControllerAdvice，则应用程序将返回包含错误消息的默认JSON响应。

我不想替换此JSON响应，但是我想在发生其他情况时记录其他信息（例如记录某些请求者的IP地址）。

是否可以使用带有@ExceptionHandler注释的方法或其他机制来做到这一点？

Answer 1

Spring MVC确实为您配置了一个异常处理程序。
默认情况下，按照类javadoc中的说明使用DefaultHandlerExceptionResolver：

HandlerExceptionResolver接口的默认实现   解决标准的Spring异常并将其转换为   相应的HTTP状态代码。

此异常解析器默认在通用Spring中启用   org.springframework.web.servlet.DispatcherServlet。

在通过用@ControllerAdvice注释类定义自定义异常处理程序时，可以扩展默认的异常处理程序，例如ResponseEntityExceptionHandler。
并且您可以知道handleException()方法中实际处理的所有异常，该方法是ResponseEntityExceptionHandler类的Facade方法：

/**
 * Provides handling for standard Spring MVC exceptions.
 * @param ex the target exception
 * @param request the current request
 */
@ExceptionHandler({
        HttpRequestMethodNotSupportedException.class,
        HttpMediaTypeNotSupportedException.class,
        HttpMediaTypeNotAcceptableException.class,
        MissingPathVariableException.class,
        MissingServletRequestParameterException.class,
        ServletRequestBindingException.class,
        ConversionNotSupportedException.class,
        TypeMismatchException.class,
        HttpMessageNotReadableException.class,
        HttpMessageNotWritableException.class,
        MethodArgumentNotValidException.class,
        MissingServletRequestPartException.class,
        BindException.class,
        NoHandlerFoundException.class,
        AsyncRequestTimeoutException.class
    })
@Nullable
public final ResponseEntity<Object> handleException(Exception ex, WebRequest request) {
    HttpHeaders headers = new HttpHeaders();
    if (ex instanceof HttpRequestMethodNotSupportedException) {
        HttpStatus status = HttpStatus.METHOD_NOT_ALLOWED;
        return handleHttpRequestMethodNotSupported((HttpRequestMethodNotSupportedException) ex, headers, status, request);
    }
    else if (ex instanceof HttpMediaTypeNotSupportedException) {
        HttpStatus status = HttpStatus.UNSUPPORTED_MEDIA_TYPE;
        return handleHttpMediaTypeNotSupported((HttpMediaTypeNotSupportedException) ex, headers, status, request);
    }
    else if (ex instanceof HttpMediaTypeNotAcceptableException) {
        HttpStatus status = HttpStatus.NOT_ACCEPTABLE;
        return handleHttpMediaTypeNotAcceptable((HttpMediaTypeNotAcceptableException) ex, headers, status, request);
    }
    else if (ex instanceof MissingPathVariableException) {
        HttpStatus status = HttpStatus.INTERNAL_SERVER_ERROR;
        return handleMissingPathVariable((MissingPathVariableException) ex, headers, status, request);
    }
    else if (ex instanceof MissingServletRequestParameterException) {
        HttpStatus status = HttpStatus.BAD_REQUEST;
        return handleMissingServletRequestParameter((MissingServletRequestParameterException) ex, headers, status, request);
    }
    else if (ex instanceof ServletRequestBindingException) {
        HttpStatus status = HttpStatus.BAD_REQUEST;
        return handleServletRequestBindingException((ServletRequestBindingException) ex, headers, status, request);
    }
    else if (ex instanceof ConversionNotSupportedException) {
        HttpStatus status = HttpStatus.INTERNAL_SERVER_ERROR;
        return handleConversionNotSupported((ConversionNotSupportedException) ex, headers, status, request);
    }
    else if (ex instanceof TypeMismatchException) {
        HttpStatus status = HttpStatus.BAD_REQUEST;
        return handleTypeMismatch((TypeMismatchException) ex, headers, status, request);
    }
    else if (ex instanceof HttpMessageNotReadableException) {
        HttpStatus status = HttpStatus.BAD_REQUEST;
        return handleHttpMessageNotReadable((HttpMessageNotReadableException) ex, headers, status, request);
    }
    else if (ex instanceof HttpMessageNotWritableException) {
        HttpStatus status = HttpStatus.INTERNAL_SERVER_ERROR;
        return handleHttpMessageNotWritable((HttpMessageNotWritableException) ex, headers, status, request);
    }
    else if (ex instanceof MethodArgumentNotValidException) {
        HttpStatus status = HttpStatus.BAD_REQUEST;
        return handleMethodArgumentNotValid((MethodArgumentNotValidException) ex, headers, status, request);
    }
    else if (ex instanceof MissingServletRequestPartException) {
        HttpStatus status = HttpStatus.BAD_REQUEST;
        return handleMissingServletRequestPart((MissingServletRequestPartException) ex, headers, status, request);
    }
    else if (ex instanceof BindException) {
        HttpStatus status = HttpStatus.BAD_REQUEST;
        return handleBindException((BindException) ex, headers, status, request);
    }
    else if (ex instanceof NoHandlerFoundException) {
        HttpStatus status = HttpStatus.NOT_FOUND;
        return handleNoHandlerFoundException((NoHandlerFoundException) ex, headers, status, request);
    }
    else if (ex instanceof AsyncRequestTimeoutException) {
        HttpStatus status = HttpStatus.SERVICE_UNAVAILABLE;
        return handleAsyncRequestTimeoutException(
                (AsyncRequestTimeoutException) ex, headers, status, request);
    }
    else {
        if (logger.isWarnEnabled()) {
            logger.warn("Unknown exception type: " + ex.getClass().getName());
        }
        HttpStatus status = HttpStatus.INTERNAL_SERVER_ERROR;
        return handleExceptionInternal(ex, null, headers, status, request);
    }
}

现在，如何重写特定异常的异常处理程序？ Spring不允许您在注解Exception的方法中多次定义@ExceptionHandler类。因此，将此映射添加到您的自定义异常处理程序中：

@ExceptionHandler(value = { HttpRequestMethodNotSupportedException.class })
protected ResponseEntity<Object> handleConflict(HttpRequestMethodNotSupportedException ex, WebRequest request) {
   ...
}

不起作用：它将阻止Spring容器成功启动。
您应该得到一个异常，例如：

Caused by: java.lang.IllegalStateException: Ambiguous @ExceptionHandler method mapped for [class org.springframework.web.HttpRequestMethodNotSupportedException]: {protected org.springframework...

为允许客户端子类覆盖实际定义的行为，Spring在protected基类的ResponseEntityExceptionHandler方法中实现了由自身捕获和处理的每个异常的逻辑。
因此，在您的情况下，您只需要覆盖handleHttpRequestMethodNotSupported()即可看到我们在此处调用的内容：

if (ex instanceof HttpRequestMethodNotSupportedException) {
    HttpStatus status = HttpStatus.METHOD_NOT_ALLOWED;
    return handleHttpRequestMethodNotSupported((HttpRequestMethodNotSupportedException) ex, headers, status, request);
}

例如：

@ControllerAdvice
public class MyExceptionHandler extends ResponseEntityExceptionHandler {

    @Override
    protected ResponseEntity<Object> handleHttpRequestMethodNotSupported(HttpRequestMethodNotSupportedException ex, HttpHeaders headers, HttpStatus status,
            WebRequest request) {    
        // do your processing
         ...
        // go one (or no) to execute the logic defined in the base class 
        return super.handleHttpRequestMethodNotSupported(ex, headers, status, request);
    }
}

Answer 2

感谢davidxxx给出的答案和示例。他们帮助了我很多。谢谢！我是这样做的，对我有用。这是一个示例：

    @ControllerAdvice
    public class AppExceptionHandler extends ResponseEntityExceptionHandler {
        @ExceptionHandler(ResourceNotFoundException.class)
        public ResponseEntity<?> resourceNotFoundException(final ResourceNotFoundException ex, final WebRequest request) {
            final ErrorDetails errorDetails = new ErrorDetails(new Date(), ex.getMessage(), request.getDescription(false));
            return new ResponseEntity<>(errorDetails, HttpStatus.NOT_FOUND);
        }
    @ExceptionHandler(ResourceAlreadyExistsFoundException.class)
    public ResponseEntity<?> resourceAlreadyExistsFoundException(final ResourceAlreadyExistsFoundException ex, final WebRequest request) {
        final ErrorDetails errorDetails = new ErrorDetails(new Date(), ex.getMessage(), request.getDescription(false));
        return new ResponseEntity<>(errorDetails, HttpStatus.BAD_REQUEST);
    }

    @ExceptionHandler(ConstraintViolationException.class)
    ResponseEntity<?> onConstraintValidationException(
            ConstraintViolationException e) {
        List<ErrorDetails> errors = new ArrayList<>();
        for (ConstraintViolation violation : e.getConstraintViolations()) {
            errors.add(
                    new ErrorDetails(new Date(), violation.getPropertyPath().toString(), violation.getMessage()));
        }
        return new ResponseEntity<>(errors, HttpStatus.BAD_REQUEST);
    }

    @Override
    protected ResponseEntity<Object> handleMethodArgumentNotValid(MethodArgumentNotValidException ex, HttpHeaders headers, HttpStatus status, WebRequest request) {
        ArrayList<ErrorDetails> errors = new ArrayList<>();
        for (FieldError fieldError : ex.getBindingResult().getFieldErrors()) {
            errors.add(
                    new ErrorDetails(new Date(), fieldError.getField(), fieldError.getDefaultMessage()));
        }
        return new ResponseEntity<>(errors, HttpStatus.BAD_REQUEST);
    }

    @ExceptionHandler(Exception.class)
    public ResponseEntity<?> globleExcpetionHandler(final Exception ex, final WebRequest request) {
        final ErrorDetails errorDetails = new ErrorDetails(new Date(), ex.getMessage(), request.getDescription(false));
        return new ResponseEntity<>(errorDetails, HttpStatus.INTERNAL_SERVER_ERROR);
    }
}

覆盖标准Spring MVC异常的处理行为

2 个答案: