java - Spring MVC - 处理 HttpMediaTypeNotAcceptableException 时如何设置返回媒体类型？

Question

我有一个 Spring 3.2 MVC REST 服务，它通过扩展 ResponseEntityExceptionHandler 来实现错误处理。这处理 standard Spring exceptions ，并将根据客户端的请求，以适当的 HTTP 状态和 XML 或 JSON 格式的自定义“错误”ResponseEntity 对象进行响应。这对于除 HttpMediaTypeNotAcceptableException 之外的所有标准异常都非常有效。

我遇到的这个异常的问题是，它首先抛出的原因是无法从请求中确定响应媒体类型(application/xml、application/json 等)。如果我尝试为此异常返回“错误”ResponseEntity 对象，它将失败，因为无法确定响应媒体类型(这就是首先处理此异常的原因)...并且基本上得到另一个 HttpMediaTypeNotAcceptableException 从我的 ExceptionHandler 中抛出。

我需要在处理 HttpMediaTypeNotAcceptableException 时找到一种方法来指定有效的响应媒体类型，以便 ResponseEntity 将其发送给客户端。由于无法确定请求的媒体类型，这可能只是我的服务的默认值(application/xml)

有什么想法吗？

Answer 1

我在开发中发现了同样的问题，要解决这个问题，您需要在 controllerAdvicer 的所有注释为 @ExceptionHandler 的方法中出现的错误消息的响应正文中指定> 内容类型:

例如:您的接收 header 接受:application/pdf，但您的应用程序生成application/json。

类GlobalExceptionHandler 用@ControllerAdvice注释来管理特定的主体响应:

    package com.obs.sfu.exception;

import javax.validation.ConstraintViolationException;

import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.web.HttpMediaTypeNotAcceptableException;
import org.springframework.web.HttpMediaTypeNotSupportedException;
import org.springframework.web.HttpRequestMethodNotSupportedException;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.context.request.WebRequest;
import org.springframework.web.servlet.NoHandlerFoundException;
import org.springframework.web.servlet.mvc.method.annotation.ResponseEntityExceptionHandler;
import org.springframework.ws.soap.client.SoapFaultClientException;

@ControllerAdvice
public class GlobalExceptionHandler extends ResponseEntityExceptionHandler {

    private static final String SIZE_MUST_BE_FROM_1_TO_15_CHARACTERS = "Size must be from 1 to 15 characters";
    private static final int CODE_INTERNAL_SERVER_ERROR = 1;
    private static final String MESSAGE_INTERNAL_SERVER_ERROR = "Internal error";
    private static final String DESCRIPTION_INTERNAL_SERVER_ERROR = "Generic failure message";

    private static final int CODE_SERVICE_UNAVAILABLE = 5;
    private static final String MESSAGE_SERVICE_UNAVAILABLE = "The service is temporarily unavailable";
    private static final String DESCRIPTION_SERVICE_UNAVAILABLE = "The service can not handle the call.";

    private static final int CODE_UNSUPPORTED_MEDIA_TYPE = 68;
    private static final String MESSAGE_UNSUPPORTED_MEDIA_TYPE = "Unsupported Media Type";
    private static final String DESCRIPTION_UNSUPPORTED_MEDIA_TYPE = "The format of the posted body is not supported by the endpoint.";

    private static final int CODE_NOT_FOUND = 60;
    private static final String MESSAGE_NOT_FOUND = "Resource not found";
    private static final String DESCRIPTION_NOT_FOUND = "The Requested URI or the requested resource does not exist.";

    private static final int CODE_METHOD_NOT_ALLOWED = 61;
    private static final String MESSAGE_METHOD_NOT_ALLOWED = "Method not allowed";
    private static final String DESCRIPTION_METHOD_NOT_ALLOWED = "The URI does not support the requested method. The available methods should be set in the response header 'Allow'";

    private static final int CODE_NOT_ACCEPTABLE = 62;
    private static final String MESSAGE_NOT_ACCEPTABLE = "Not acceptable";
    private static final String DESCRIPTION_NOT_ACCEPTABLE = "The Accept incoming header does not match any available content-type.";

    private static final int CODE_CONSTRAINT_VIOLATION_FIELD = 20;
    private static final String MESSAGE_INVALID_BODY_FIELD = "Invalid Via field";

    private static final String HEADER_ALLOW = "Allow";
    private static final String HEADER_ALLOW_VALUE = "GET, OPTIONS";

    @Override
    protected ResponseEntity<Object> handleNoHandlerFoundException(NoHandlerFoundException ex, HttpHeaders headers,
            HttpStatus status, WebRequest request) {
        ErrorDetails errorDetails = new ErrorDetails(request.getContextPath(), MESSAGE_NOT_FOUND, DESCRIPTION_NOT_FOUND,
                CODE_NOT_FOUND);
        return ResponseEntity.status(status).contentType(MediaType.APPLICATION_JSON).body(errorDetails);
    }

    @Override
    protected ResponseEntity<Object> handleHttpRequestMethodNotSupported(HttpRequestMethodNotSupportedException ex,
            HttpHeaders headers, HttpStatus status, WebRequest request) {
        ErrorDetails errorDetails = new ErrorDetails(request.getContextPath(), MESSAGE_METHOD_NOT_ALLOWED,
                DESCRIPTION_METHOD_NOT_ALLOWED, CODE_METHOD_NOT_ALLOWED);
        HttpHeaders responseHeaders = new HttpHeaders();
        responseHeaders.set(HEADER_ALLOW, HEADER_ALLOW_VALUE);
        return ResponseEntity.status(status).headers(responseHeaders).contentType(MediaType.APPLICATION_JSON)
                .body(errorDetails);
    }

    @Override
    protected ResponseEntity<Object> handleHttpMediaTypeNotSupported(HttpMediaTypeNotSupportedException ex,
            HttpHeaders headers, HttpStatus status, WebRequest request) {
        ErrorDetails errorDetails = new ErrorDetails(request.getContextPath(), MESSAGE_UNSUPPORTED_MEDIA_TYPE,
                DESCRIPTION_UNSUPPORTED_MEDIA_TYPE, CODE_UNSUPPORTED_MEDIA_TYPE);
        HttpHeaders responseHeaders = new HttpHeaders();
        responseHeaders.set("Accept", MediaType.APPLICATION_JSON_VALUE);
        return ResponseEntity.status(status).headers(responseHeaders).contentType(MediaType.APPLICATION_JSON)
                .body(errorDetails);
    }

    @Override
    protected ResponseEntity<Object> handleHttpMediaTypeNotAcceptable(HttpMediaTypeNotAcceptableException ex,
            HttpHeaders headers, HttpStatus status, WebRequest request) {
        ErrorDetails errorDetails = new ErrorDetails(request.getContextPath(), MESSAGE_NOT_ACCEPTABLE,
                DESCRIPTION_NOT_ACCEPTABLE, CODE_NOT_ACCEPTABLE);
        return ResponseEntity.status(status).contentType(MediaType.APPLICATION_JSON).body(errorDetails);
    }

    @ExceptionHandler(ConstraintViolationException.class)
    public ResponseEntity<Object> handleConstraintViolation(ConstraintViolationException ex, WebRequest request) {
        ErrorDetails errorDetails = new ErrorDetails(request.getContextPath(), MESSAGE_INVALID_BODY_FIELD,
                SIZE_MUST_BE_FROM_1_TO_15_CHARACTERS, CODE_CONSTRAINT_VIOLATION_FIELD);
        return ResponseEntity.status(HttpStatus.BAD_REQUEST).contentType(MediaType.APPLICATION_JSON).body(errorDetails);
    }

    @ExceptionHandler(SoapFaultClientException.class)
    public ResponseEntity<Object> handleSoapFaultClient(Exception ex, WebRequest request) {
        ErrorDetails errorDetails = new ErrorDetails(request.getContextPath(), MESSAGE_SERVICE_UNAVAILABLE,
                DESCRIPTION_SERVICE_UNAVAILABLE, CODE_SERVICE_UNAVAILABLE);
        return ResponseEntity.status(HttpStatus.SERVICE_UNAVAILABLE).contentType(MediaType.APPLICATION_JSON)
                .body(errorDetails);
    }

    @ExceptionHandler(Exception.class)
    public ResponseEntity<Object> handleGlobalException(Exception ex, WebRequest request) {
        ErrorDetails errorDetails = new ErrorDetails(request.getContextPath(), MESSAGE_INTERNAL_SERVER_ERROR,
                DESCRIPTION_INTERNAL_SERVER_ERROR, CODE_INTERNAL_SERVER_ERROR);
        return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).contentType(MediaType.APPLICATION_JSON)
                .body(errorDetails);
    }
}

文件application.properties需要这些属性来管理NoHandlerFoundException(throwExceptionIfNoHandlerFound):

spring:
  mvc: 
    throw-exception-if-no-handler-found: true
    static-path-pattern: /swagger* # to available swagger-ui.html