Spring MVC 3.2 异常响应映射

Question

Spring 3.2.15，此处是基于 MVC 的 REST API（不是 Spring Boot，很遗憾！）。我正在尝试实现满足以下条件的异常映射器/处理程序：

• 无论发生什么（成功或错误），Spring 应用程序始终返回MyAppResponse 的响应实体（见下文）；和
• 在成功处理请求的情况下，返回 HTTP 状态 200（典型）；和
• 在处理请求发生异常时，我需要控制特定异常到特定HTTP状态码的映射
  • Spring MVC 框架错误（如BlahException）必须映射到 HTTP 422
  • 自定义app异常，比如我的FizzBuzzException有自己的状态映射方案：
    • FizzBuzzException -> HTTP 401
    • FooBarException -> HTTP 403
    • OmgException -> HTTP 404
  • 所有其他异常，即非 Spring 异常和非自定义应用程序异常（上面列出的 3 个）都应该产生 HTTP 500

MyAppResponse 对象在哪里：

// Groovy pseudo-code
@Canonical
class MyAppResponse {
    String detail
    String randomNumber
}

它似乎像ResponseEntityExceptionHandler 可能能够为我做到这一点，但我没有看到森林通过树木w.r.t。它是如何传递参数的。我希望我可以做类似的事情：

// Groovy-pseudo code
@ControllerAdvice
class MyAppExceptionMapper extends ResponseEntityExceptionHandler {
    ResponseEntity<Object> handleFizzBuzzException(FizzBuzzException fbEx, HttpHeaders headers, HttpStatus status) {
        // TODO: How to reset status to 401?
        status = ???

        new ResponseEntity(fbEx.message, headers, status)
    }

    ResponseEntity<Object> handleFooBarException(FooBarException fbEx, HttpHeaders headers, HttpStatus status) {
        // TODO: How to reset status to 403?
        status = ???

        new ResponseEntity(fbEx.message, headers, status)
    }

    ResponseEntity<Object> handleOmgException(OmgException omgEx, HttpHeaders headers, HttpStatus status) {
        // TODO: How to reset status to 404?
        status = ???

        new ResponseEntity(omgEx.message, headers, status)
    }

    // Now map all Spring-generated exceptions to 422
    ResponseEntity<Object> handleAllSpringExceptions(SpringException springEx, HttpHeaders headers, HttpStatus status) {
        // TODO: How to reset status to 422?
        status = ???

        new ResponseEntity(springEx.message, headers, status)
    }

    // Everything else is a 500...
    ResponseEntity<Object> handleAllOtherExceptions(Exception ex, HttpHeaders headers, HttpStatus status) {
        // TODO: How to reset status to 500?
        status = ???

        new ResponseEntity("Whoops, something happened. Lol.", headers, status)
    }
}

知道如何完全实现此映射逻辑以及实体是MyAppResponse 实例而不仅仅是字符串的要求吗？

那么，使用 @ControllerAdvice 注释类是我配置 Spring 以使用它唯一需要做的事情吗？

Answer 1

要减少@bond-java-bond 答案，您不需要自己构建ResponseEntity：

1. 为每个handleSomeException 方法使用@ResponseStatus（例如@ResponseStatus(HttpStatus.UNAUTHORIZED)）
2. 从这些方法返回自定义 MyAppResponse

但是如果每种异常都会以相同的方式处理（仅通过 HTTP 状态区分）我建议减少 MyAppExceptionMapper 像这样：

@ControllerAdvice
public class MyAppExceptionMapper {
    private final Map<Class<?>, HttpStatus> map;
    {
        map = new HashMap<>();
        map.put(FizzBuzzException.class, HttpStatus.UNAUTHORIZED);
        map.put(FooBarException.class, HttpStatus.FORBIDDEN);
        map.put(NoSuchRequestHandlingMethodException.class, HttpStatus.UNPROCESSABLE_ENTITY);
        /* List Spring specific exceptions here as @bond-java-bond suggested */
        map.put(Exception.class, HttpStatus.INTERNAL_SERVER_ERROR);
    }

    // Handle all exceptions
    @ExceptionHandler(Exception.class)
    @ResponseBody
    public ResponseEntity<MyAppResponse> handleException(Exception exception) {
        MyAppResponse response = new MyAppResponse();
        // Fill response with details

        HttpStatus status = map.get(exception.getClass());
        if (status == null) {
            status = map.get(Exception.class);// By default
        }

        return new ResponseEntity<>(response, status);
    }
}

优点：

1. 很短。
2. 没有代码重复。
3. 稍微更有效。
4. 易于扩展。

另外，您可以将映射配置移到外部并注入。

如何配置 MVC Dispatcher Servlet

首先，检查mvc-dispatcher-servlet.xml（或来自web.xml 的另一个contextConfigLocation）是否包含：

<context:component-scan base-package="base.package"/>
<mvc:annotation-driven/>

其次，检查@ControllerAdvice注解类和@Controller注解类是否都属于base.package的子包。

有关详细信息，请参阅 Exception Handling in Spring MVC 或 Spring MVC @ExceptionHandler Example 上的完整示例。

Answer 2

首先错误/异常处理程序应该不担心成功响应。

因此，成功响应的责任应该在于使用@RequestMapping 注释的控制器（普通或 REST 控制器）方法，如下所示

@RequestMapping(value = "/demo", method = RequestMethod.GET)
@ResponseStatus(value = HttpStatus.OK)
public MyAppResponse doSomething() { .... }

要映射带有异常的特定 HTTP 响应代码，只需编写如下 @ControllerAdvice（无需额外配置）

@ControllerAdvice
public class CustomExceptionHandler {

    // Handle FizzBuzzException with status code as 401
    @ExceptionHandler(value = FizzBuzzException.class)
    @ResponseBody
    public ResponseEntity<MyAppResponse> handleException(FizzBuzzException ex) {
        return new ResponseEntity<MyAppResponse>(buildResponse(ex), HttpStatus.UNAUTHORIZED);
    }

    // Handle FooBarException with status code as 403
    @ExceptionHandler(value = FooBarException.class)
    @ResponseBody
    public ResponseEntity<MyAppResponse> handleException(FooBarException ex) {
        return new ResponseEntity<MyAppResponse>(buildResponse(ex), HttpStatus.FORBIDDEN);
    }

    // Handle OmgException with status code as 404
    @ExceptionHandler(value = OmgException.class)
    @ResponseBody
    public ResponseEntity<MyAppResponse> handleException(OmgException ex) {
        return new ResponseEntity<MyAppResponse>(buildResponse(ex), HttpStatus.NOT_FOUND);
    }

    // handle Spring MVC specific exceptions with status code 422
    @ExceptionHandler(value = {NoSuchRequestHandlingMethodException.class, 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})
    @ResponseBody
    public ResponseEntity<MyAppResponse> handleException(Exception ex) {
        return new ResponseEntity<MyAppResponse>(buildResponse(ex), HttpStatus.UNPROCESSABLE_ENTITY);
    }

    // Handle rest of the exception(s) with status code as 500
    @ExceptionHandler(value = Exception.class)
    @ResponseBody
    public ResponseEntity<MyAppResponse> handleException(Exception ex) {
        return new ResponseEntity<MyAppResponse>(buildResponse(ex), HttpStatus.INTERNAL_SERVER_ERROR);
    }

    private MyAppResponse buildResponse(Throwable t) {
        MyAppResponse response = new MyAppResponse();
        // supply value to response object
        return response;
    }
}

如果需要任何进一步的信息，请在 cmets 中告知。

P.S.：Spring MVC 异常列表reference