Springmvc全局异常处理器

1.创建一个类，实现HandlerExceptionResolver

public class ExceptionResolver implements HandlerExceptionResolver {

    private HttpMessageConverter<ExceptionResultInfo> mappingJacksonHttpMessageConverter;

    @Override
    public ModelAndView resolveException(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) {
        // 输出 异常信息
        ex.printStackTrace();
        // 转成springmvc底层对象（就是对action方法的封装对象，只有一个方法）
        HandlerMethod handlerMethod = (HandlerMethod) handler;
        // 取出方法
        Method method = handlerMethod.getMethod();
        //判断方法是否返回JSON
        //只要方法中含有ResponseBody就是返回的JSON
        ResponseBody responseBody = AnnotationUtils.findAnnotation(method,ResponseBody.class);

        ModelAndView modelAndView = new ModelAndView();
        if(responseBody != null){//不为空表示是JSON
            Body body = null;
            //解析异常信息为JSON
            ExceptionResultInfo exceptionResultInfo = null;
            //判断异常是否是自定义的异常
            if(ex instanceof SystemException){
                //如果是，抛出自定义异常
                body = new Body();
                body.setMsgCode(((SystemException) ex).getMsgCode());
                body.setMsgDes(((SystemException) ex).getMsgDes());
            }else{
                //如果不是自定义异常，则直接抛出未知错误,
                body = new Body();
                body.setMsgCode("0x00001");
                body.setMsgDes("未知错误");
            }
            exceptionResultInfo = new ExceptionResultInfo(body,"00");
            //输出JSON到页面
            HttpOutputMessage outputMesage = new ServletServerHttpResponse(response);
            try {
                mappingJacksonHttpMessageConverter.write(exceptionResultInfo, MediaType.APPLICATION_JSON,outputMesage);
            } catch (IOException e) {
                e.printStackTrace();
            }
            return new ModelAndView();
        }else{//为空，表示返回的是JSP页面
            //直接跳转到错误页面
            modelAndView.setViewName("/error/error");// 逻辑视图名
        }
        return modelAndView;
    }

    public HttpMessageConverter<ExceptionResultInfo> getMappingJacksonHttpMessageConverter() {
        return mappingJacksonHttpMessageConverter;
    }

    public void setMappingJacksonHttpMessageConverter(HttpMessageConverter<ExceptionResultInfo> mappingJacksonHttpMessageConverter) {
        this.mappingJacksonHttpMessageConverter = mappingJacksonHttpMessageConverter;
    }
}

2.springmvc.XML中

<bean id="mappingJacksonHttpMessageConverter" class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter">
   <property name="supportedMediaTypes">
      <list>
         <value>text/html;charset=UTF-8</value>
      </list>
   </property>
</bean>

<!-- 统一异常处理类 -->
<bean id="handlerExceptionResolver" class="pnc.mesadmin.interceptor.ExceptionResolver">
   <!-- 注入一个json转换器 -->
   <property name="mappingJacksonHttpMessageConverter" ref="mappingJacksonHttpMessageConverter" />
</bean>

3.web.XML中

<servlet>
    <servlet-name>springmvc</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <init-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>classpath:spring-mvc.xml</param-value>
    </init-param>
    <init-param>
        <param-name>detectAllHandlerExceptionResolvers</param-name>
        <param-value>false</param-value>
    </init-param>
</servlet>