资料来源于：http://blog.csdn.net/m13321169565/article/details/7641978
在使用web开发和API 开发都使用到异常的处理，web 异常后跳到指定的错误页面，那么API或AJAX调用需要返回JSON的错误信息，所以我们需要一个统一的异常处理机制来管理这些异常！
1.定义自己的异常处理类
import java.io.IOException;
import java.lang.reflect.Method;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
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;
/**
* 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。
*
* @author dongjian
*
* */
public class AnnotationHandlerMethodExceptionResolver extends ExceptionHandlerExceptionResolver {
private String defaultErrorView;
public String getDefaultErrorView() {
return defaultErrorView;
}
public void setDefaultErrorView(String defaultErrorView) {
this.defaultErrorView = defaultErrorView;
}
/***
* 异常后跳转到页面
*/
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;
}
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) { }
}
}
return handleResponseBody(returnValue, request, response);
} catch (Exception e) {
return null;
}
}
if(returnValue.getViewName() == null){
returnValue.setViewName(defaultErrorView);
}
return returnValue;
}
/**
* 异常后 返回json
* @param returnValue
* @param request
* @param response
* @return
* @throws ServletException
* @throws IOException
*/
@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;
}
}
2.在spring MVC 配置中添加如下配置
<!-- ResponseBody 的类型 -->
<bean
id="messageConverters" class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter">
<property name="supportedMediaTypes">
<list>
<value>application/json;charset=UTF-8</value>
</list>
</property>
</bean>
<bean id="handlerAdapter"
class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter">
<property name="cacheSeconds" value="0" />
<property name="messageConverters" ref="messageConverters" />
</bean>
<!-- 设置自定义异常处理 -->
<bean id="handlerExceptionResolver" class="com.chengkun.base.exception.AnnotationHandlerMethodExceptionResolver">
<property name="defaultErrorView" value="error.jsp"/><!-- 错误页面 -->
<property name="messageConverters" ref="messageConverters"/> <!--JSON 处理的messageConverters->
</bean>
3.修改web.xml 禁止自动注册，让其使用我们自定义的类
<servlet> <servlet-name>spring-mvc</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <init-param> <param-name>contextConfigLocation</param-name> <param-value>classpath:spring/spring-mvc.xml</param-value> </init-param> <!-- 取消其自动注册的异常解析器 --> <init-param> <param-name>detectAllHandlerExceptionResolvers</param-name> <param-value>false</param-value> </init-param> <load-on-startup>1</load-on-startup> </servlet>
4.在BaseController 中加入异常控制，所有controller必须继承BaseController
/**
* 异常控制，可以根据不同的异常类型 在此定义不同的错误消息和操作
* */
@ExceptionHandler(Exception.class)
@ResponseStatus(value=HttpStatus.INTERNAL_SERVER_ERROR)
public ModelAndView handleException(Exception ex, HttpServletRequest request) {
return new ModelAndView().addObject(new ResultPojo(500));
}
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