背景：
在和第三方对接的时候，其要求接口格式必须和文档要求的一致，并且错误格式也得和文档一致。正常响应很好处理，难点就在对异常情况下响应信息的封装了。springboot中可以使用ControllerAdvice和ExceptionHandler这两个注解来做全局异常，这种方式比较便捷，但是也有一个问题：
ContollerAdvice只能拦截控制器中的异常，换言之，只能拦截500之类的异常，但是对于404这样不会进入控制器处理的异常不起作用。所以我仿造springboot默认的全局处理类BasicController实现全局的异常处理，这样就能很好的按照自己的需求处理异常了。
原理：
springboot会将所有的异常发送到路径为server.error.path（application.properties中可配置，默认为”/error”）的控制器方法中进行处理，页面请求和ajax请求会分别打到对应的处理方法上。具体的处理可查看BasicErrorController的源代码：
/*
* Copyright 2012-2020 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* https://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.boot.autoconfigure.web.servlet.error;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.boot.autoconfigure.web.ErrorProperties;
import org.springframework.boot.autoconfigure.web.ErrorProperties.IncludeStacktrace;
import org.springframework.boot.web.servlet.error.ErrorAttributes;
import org.springframework.boot.web.servlet.server.AbstractServletWebServerFactory;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Controller;
import org.springframework.util.Assert;
import org.springframework.web.HttpMediaTypeNotAcceptableException;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;
/**
* Basic global error {@link Controller @Controller}, rendering {@link ErrorAttributes}.
* More specific errors can be handled either using Spring MVC abstractions (e.g.
* {@code @ExceptionHandler}) or by adding servlet
* {@link AbstractServletWebServerFactory#setErrorPages server error pages}.
*
* @author Dave Syer
* @author Phillip Webb
* @author Michael Stummvoll
* @author Stephane Nicoll
* @since 1.0.0
* @see ErrorAttributes
* @see ErrorProperties
*/
@Controller
@RequestMapping("${server.error.path:${error.path:/error}}")
public class BasicErrorController extends AbstractErrorController {
private final ErrorProperties errorProperties;
/**
* Create a new {@link BasicErrorController} instance.
* @param errorAttributes the error attributes
* @param errorProperties configuration properties
*/
public BasicErrorController(ErrorAttributes errorAttributes, ErrorProperties errorProperties) {
this(errorAttributes, errorProperties, Collections.emptyList());
}
/**
* Create a new {@link BasicErrorController} instance.
* @param errorAttributes the error attributes
* @param errorProperties configuration properties
* @param errorViewResolvers error view resolvers
*/
public BasicErrorController(ErrorAttributes errorAttributes, ErrorProperties errorProperties,
List<ErrorViewResolver> errorViewResolvers) {
super(errorAttributes, errorViewResolvers);
Assert.notNull(errorProperties, "ErrorProperties must not be null");
this.errorProperties = errorProperties;
}
@Override
public String getErrorPath() {
return this.errorProperties.getPath();
}
@RequestMapping(produces = MediaType.TEXT_HTML_VALUE)
public ModelAndView errorHtml(HttpServletRequest request, HttpServletResponse response) {
HttpStatus status = getStatus(request);
Map<String, Object> model = Collections
.unmodifiableMap(getErrorAttributes(request, isIncludeStackTrace(request, MediaType.TEXT_HTML)));
response.setStatus(status.value());
ModelAndView modelAndView = resolveErrorView(request, response, status, model);
return (modelAndView != null) ? modelAndView : new ModelAndView("error", model);
}
@RequestMapping
public ResponseEntity<Map<String, Object>> error(HttpServletRequest request) {
HttpStatus status = getStatus(request);
if (status == HttpStatus.NO_CONTENT) {
return new ResponseEntity<>(status);
}
Map<String, Object> body = getErrorAttributes(request, isIncludeStackTrace(request, MediaType.ALL));
return new ResponseEntity<>(body, status);
}
@ExceptionHandler(HttpMediaTypeNotAcceptableException.class)
public ResponseEntity<String> mediaTypeNotAcceptable(HttpServletRequest request) {
HttpStatus status = getStatus(request);
return ResponseEntity.status(status).build();
}
/**
* Determine if the stacktrace attribute should be included.
* @param request the source request
* @param produces the media type produced (or {@code MediaType.ALL})
* @return if the stacktrace attribute should be included
*/
protected boolean isIncludeStackTrace(HttpServletRequest request, MediaType produces) {
IncludeStacktrace include = getErrorProperties().getIncludeStacktrace();
if (include == IncludeStacktrace.ALWAYS) {
return true;
}
if (include == IncludeStacktrace.ON_TRACE_PARAM) {
return getTraceParameter(request);
}
return false;
}
/**
* Provide access to the error properties.
* @return the error properties
*/
protected ErrorProperties getErrorProperties() {
return this.errorProperties;
}
}
实现：
实现原理很简单，就是模仿BasicErrorController的实现思路，继承AbstractErrorController并重写error方法，然后再配置文件里面进行配置覆盖默认配置就好了。
1.继承AbstractErrorController并重写error方法
package com.innovamed.exception;
import java.util.Collections;
import java.util.Map;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.autoconfigure.web.ErrorProperties;
import org.springframework.boot.autoconfigure.web.ErrorProperties.IncludeStacktrace;
import org.springframework.boot.autoconfigure.web.ServerProperties;
import org.springframework.boot.autoconfigure.web.servlet.error.AbstractErrorController;
import org.springframework.boot.web.servlet.error.ErrorAttributes;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Controller;
import org.springframework.web.HttpMediaTypeNotAcceptableException;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;
/***
*
* Copyright: Copyright (c) 2020 Jun_Zhou
*
* @ClassName: CustomErrHandleController.java
* @Description: 自定义的异常处理控制器，用于覆盖默认端BasicErrorController;
*
* @version: v1.0.0
* @author: JunZhou
* @Email: 1769676159@qq.com
* @Site: CERNO
* @date: 2020年4月26日 下午2:58:36
*/
@Controller
@RequestMapping("/server/error")
public class CustomErrHandleController extends AbstractErrorController
{
private ErrorProperties errorProperties = null;
/**
* Creates an instance.
*
* @param request HttpRequest of each call
* @param errorAttributes ErrorAttributes of each call
* @param serverProperties ServerProperties of each call
*/
@Autowired
public CustomErrHandleController(ErrorAttributes errorAttributes, ServerProperties serverProperties) {
super(errorAttributes);
this.errorProperties = serverProperties.getError();
}
@Override
public String getErrorPath() {
return this.errorProperties.getPath();
}
@RequestMapping(produces = MediaType.TEXT_HTML_VALUE)
public ModelAndView errorHtml(HttpServletRequest request, HttpServletResponse response) {
HttpStatus status = getStatus(request);
Map<String, Object> model = Collections
.unmodifiableMap(getErrorAttributes(request, isIncludeStackTrace(request, MediaType.TEXT_HTML)));
response.setStatus(status.value());
ModelAndView modelAndView = resolveErrorView(request, response, status, model);
return (modelAndView != null) ? modelAndView : new ModelAndView("error", model);
}
@RequestMapping("/json-ex")
public ResponseEntity<Map<String, Object>> error(HttpServletRequest request) { HttpStatus status = getStatus(request); if (status == HttpStatus.NO_CONTENT) { return new ResponseEntity<>(status); } Map<String, Object> body = getErrorAttributes(request, isIncludeStackTrace(request, MediaType.ALL)); body.put("author", "176967659@qq.com"); return new ResponseEntity<>(body, status); }
@ExceptionHandler(HttpMediaTypeNotAcceptableException.class)
public ResponseEntity<String> mediaTypeNotAcceptable(HttpServletRequest request) {
HttpStatus status = getStatus(request);
return ResponseEntity.status(status).build();
}
/**
* Determine if the stacktrace attribute should be included.
* @param request the source request
* @param produces the media type produced (or {@code MediaType.ALL})
* @return if the stacktrace attribute should be included
*/
protected boolean isIncludeStackTrace(HttpServletRequest request, MediaType produces) {
IncludeStacktrace include = getErrorProperties().getIncludeStacktrace();
if (include == IncludeStacktrace.ALWAYS) {
return true;
}
if (include == IncludeStacktrace.ON_TRACE_PARAM) {
return getTraceParameter(request);
}
return false;
}
/**
* Provide access to the error properties.
* @return the error properties
*/
protected ErrorProperties getErrorProperties() {
return this.errorProperties;
}
}
2、再SpringBoot中添加配置，覆盖默认配置。
参考文章：
1、springboot继承AbstractErrorController实现全局的异常处理
2、SpringBoot 自定义错误处理器
