springMVC全局Exception异常处理SimpleMappingExceptionResolver

/**
 * 对controller异常进行全局处理
 * 区分了对普通请求和ajax请求的异常处理，普通请求返回到配置的errorCode页面，或者返回到指定的页面
 * @author
 * 
 */
public class CustomException extends SimpleMappingExceptionResolver {
    private final transient Logger logger = LoggerFactory.getLogger(getClass());

    @Override
    protected ModelAndView doResolveException(HttpServletRequest request,
            HttpServletResponse response, Object handler, Exception ex) {
        String viewName = determineViewName(ex, request);
        if (viewName != null) {// JSP格式返回
            //增加普通提交返回到自己页面errorPage
            String errorPage = String.valueOf(request.getAttribute("errorPage"));
            //回到自己的页面
            if(StringUtils.isNotBlank(errorPage)){
                viewName = errorPage;
            }
            if (!(request.getHeader("accept").indexOf("application/json") > -1 || (request
                    .getHeader("X-Requested-With") != null && request
                    .getHeader("X-Requested-With").indexOf("XMLHttpRequest") > -1))) {
                // 如果不是异步请求
                // Apply HTTP status code for error views, if specified.
                // Only apply it if we‘re processing a top-level request.
                Integer statusCode = determineStatusCode(request, viewName);
                if (statusCode != null) {
                    applyStatusCodeIfPossible(request, response, statusCode);
                }
                return getModelAndView(viewName, ex, request);
            } else {// JSON格式返回
                try {
                    Map<String, Object> jsonMap = new HashMap<String, Object>();
                    // 返回是错误
                    jsonMap.put(BaseController.AJAX_RESULT, false);
                    jsonMap.put(BaseController.RESULT_MESSAGE, ex.getMessage());
                    response.setContentType("text/html;charset=UTF-8");
                    PrintWriter writer = response.getWriter();
                    writer.write(JSON.toJSONString(jsonMap));
                    writer.close();
                } catch (Exception e) {
                    logger.error("doResolveException", "系统异常！", e);
                }
                return null;

            }
        } else {
            return null;
        }
    }
}

<bean class="cn.tomcat.quickstart.exception.CustomException">  
        <!-- 定义默认的异常处理页面，当该异常类型的注册时使用 -->  
        <property name="defaultErrorView" value="error"></property>  
        <!-- 定义异常处理页面用来获取异常信息的变量名，默认名为exception -->  
        <property name="exceptionAttribute" value="ex"></property>  
        <!-- 定义需要特殊处理的异常，用类名或完全路径名作为key，异常也页名作为值 -->  
        <property name="exceptionMappings">  
            <props>  
                <prop key="IOException">error/ioexp</prop>  
                <prop key="java.sql.SQLException">error/sqlexp</prop>  
            </props>  
        </property>  
    </bean>