使用Spring中的ExceptionHandlerExceptionResolver进行统一的异常
1。 编写相关AnnotationHandlerMethodExceptionResolver异常处理类
package com.pss.res.base.exceptionresolver;
import com.pss.res.client.base.constants.BusiStatusCons;
import com.pss.res.client.base.domain.ServiceResponse;
import com.pss.res.common.util.DateHelper;
import org.springframework.core.annotation.AnnotationUtils;
import org.springframework.http.HttpInputMessage;
import org.springframework.http.HttpOutputMessage;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.http.server.ServletServerHttpRequest;
import org.springframework.http.server.ServletServerHttpResponse;
import org.springframework.util.StringUtils;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.ResponseStatus;
import org.springframework.web.method.HandlerMethod;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.mvc.method.annotation.ExceptionHandlerExceptionResolver;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.lang.reflect.Method;
import java.util.Collections;
import java.util.List;
import java.util.Map;
/**
* 不必在Controller中对异常进行处理，抛出即可，由此异常解析器统一控制。<br>
* ajax请求（有@ResponseBody的Controller）发生错误，输出JSON。<br>
* 页面请求（无@ResponseBody的Controller）发生错误，输出错误页面。<br>
* 需要与AnnotationMethodHandlerAdapter使用同一个messageConverters<br>
* Controller中需要有专门处理异常的方法。
*
*
* */
public class AnnotationHandlerMethodExceptionResolver extends ExceptionHandlerExceptionResolver {
private String defaultErrorView;
public String getDefaultErrorView() {
return defaultErrorView;
}
public void setDefaultErrorView(String defaultErrorView) {
this.defaultErrorView = defaultErrorView;
}
protected ModelAndView doResolveHandlerMethodException(HttpServletRequest request, HttpServletResponse response, HandlerMethod handlerMethod, Exception exception) {
if (handlerMethod == null) {
return null;
}
Method method = handlerMethod.getMethod();
if (method == null) {
return null;
}
//如果定义了ExceptionHandler则返回相应的Map中的数据
ModelAndView returnValue = super.doResolveHandlerMethodException(request, response, handlerMethod, exception);
ResponseBody responseBodyAnn = AnnotationUtils.findAnnotation(method, ResponseBody.class);
if (responseBodyAnn != null) {
try {
ResponseStatus responseStatusAnn = AnnotationUtils.findAnnotation(method, ResponseStatus.class);
if (responseStatusAnn != null) {
HttpStatus responseStatus = responseStatusAnn.value();
String reason = responseStatusAnn.reason();
if (!StringUtils.hasText(reason)) {
response.setStatus(responseStatus.value());
} else {
try {
response.sendError(responseStatus.value(), reason);
} catch (IOException e) { }
}
}
// 如果没有ExceptionHandler注解那么returnValue就为空
if (returnValue == null) {
ServiceResponse res = new ServiceResponse();
res.setResultCode(BusiStatusCons.STATUS_FAILURE);
res.setResultDesc("系统异常：" + exception.getLocalizedMessage());
res.setTimestamp(DateHelper.getCurrentTimeStamp(null));
handleResponseError(res, request, response);
return new ModelAndView();
}
return handleResponseBody(returnValue, request, response);
} catch (Exception e) {
return null;
}
}
if( null == returnValue) {
returnValue = new ModelAndView();
if (null == returnValue.getViewName()) {
returnValue.setViewName(defaultErrorView);
}
}
return returnValue;
}
@SuppressWarnings({ "unchecked", "rawtypes" })
private ModelAndView handleResponseBody(ModelAndView returnValue, HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
Map value = returnValue.getModelMap();
HttpInputMessage inputMessage = new ServletServerHttpRequest(request);
List<MediaType> acceptedMediaTypes = inputMessage.getHeaders().getAccept();
if (acceptedMediaTypes.isEmpty()) {
acceptedMediaTypes = Collections.singletonList(MediaType.ALL);
}
MediaType.sortByQualityValue(acceptedMediaTypes);
HttpOutputMessage outputMessage = new ServletServerHttpResponse(response);
Class<?> returnValueType = value.getClass();
List<HttpMessageConverter<?>> messageConverters = super.getMessageConverters();
if (messageConverters != null) {
for (MediaType acceptedMediaType : acceptedMediaTypes) {
for (HttpMessageConverter messageConverter : messageConverters) {
if (messageConverter.canWrite(returnValueType, acceptedMediaType)) {
messageConverter.write(value, acceptedMediaType, outputMessage);
return new ModelAndView();
}
}
}
}
if (logger.isWarnEnabled()) {
logger.warn("Could not find HttpMessageConverter that supports return type [" + returnValueType + "] and " + acceptedMediaTypes);
}
return null;
}
@SuppressWarnings({ "unchecked", "rawtypes" })
private ModelAndView handleResponseError(ServiceResponse returnValue, HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
HttpInputMessage inputMessage = new ServletServerHttpRequest(request);
List<MediaType> acceptedMediaTypes = inputMessage.getHeaders().getAccept();
if (acceptedMediaTypes.isEmpty()) {
acceptedMediaTypes = Collections.singletonList(MediaType.ALL);
}
MediaType.sortByQualityValue(acceptedMediaTypes);
HttpOutputMessage outputMessage = new ServletServerHttpResponse(response);
Class<?> returnValueType = returnValue.getClass();
List<HttpMessageConverter<?>> messageConverters = super.getMessageConverters();
if (messageConverters != null) {
for (MediaType acceptedMediaType : acceptedMediaTypes) {
for (HttpMessageConverter messageConverter : messageConverters) {
if (messageConverter.canWrite(returnValueType, acceptedMediaType)) {
messageConverter.write(returnValue, acceptedMediaType, outputMessage);
return new ModelAndView();
}
}
}
}
if (logger.isWarnEnabled()) {
logger.warn("Could not find HttpMessageConverter that supports return type [" + returnValueType + "] and " + acceptedMediaTypes);
}
return null;
}
}
其中以下的代码，需要根据具体情况进行改变。
// 如果没有ExceptionHandler注解那么returnValue就为空
if (returnValue == null) {
ServiceResponse res = new ServiceResponse();
res.setResultCode(BusiStatusCons.STATUS_FAILURE);
res.setResultDesc("系统异常：" + exception.getLocalizedMessage());
res.setTimestamp(DateHelper.getCurrentTimeStamp(null));
handleResponseError(res, request, response);
return new ModelAndView();
}
2。 xml配置文件中，需要进行的相关配置操作，如下：
<bean id="handlerExceptionResolver" class="com.pss.res.base.exceptionresolver.AnnotationHandlerMethodExceptionResolver"> <property name="defaultErrorView" value="error/500"/> <!--错误页面--> <property name="messageConverters"> <list> <bean class="org.springframework.http.converter.ByteArrayHttpMessageConverter" /> <!-- JSON转换器无需设置mediaType,由外部客户端调用时，手动设置相关mediaType --> <bean class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter" /> </list> </property> </bean>
3。 测试类中，只要controller中有异常抛出，即会被捕获，并显示在浏览器中。
@Controller
@RequestMapping("/exeHandler")
public class ExeHandlerController {
@RequestMapping(value="/test")
public @ResponseBody Object getAllIndusType(IndusTypeReqVO indusTypeReqVO) throws Exception{
System.err.println("cccccc");
throw new Exception("这边出错了。");
// return null;
}
}