SpringMVC 使用 HandlerExceptionResolver 进行全局异常处理

package org.jeecgframework.core.common.exception;
import java.io.IOException;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.util.HashMap;
import java.util.Map;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.log4j.Logger;
import org.jeecgframework.core.common.model.json.AjaxJson;
import org.jeecgframework.core.util.ExceptionUtil;
import org.jeecgframework.core.util.JSONHelper;
import org.jeecgframework.core.util.oConvertUtils;
import org.jeecgframework.web.system.service.SystemService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import org.springframework.web.servlet.HandlerExceptionResolver;
import org.springframework.web.servlet.ModelAndView;

/**
 * spring mvc 全局处理异常捕获 根据请求区分ajax和普通请求，分别进行响应.
 * 第一、异常信息输出到日志中。
 * 第二、截取异常详细信息的前50个字符，写入日志表中t_s_log。
 */
@Component
public class GlobalExceptionResolver implements HandlerExceptionResolver {
    @Autowired
    private SystemService systemService;
    //记录日志信息
    private static final Logger log = Logger
            .getLogger(GlobalExceptionResolver.class);
    //记录数据库最大字符长度
    private static final int WIRTE_DB_MAX_LENGTH = 1500;
    //记录数据库最大字符长度
    private static final short LOG_LEVEL = 6;
    //记录数据库最大字符长度
    private static final short LOG_OPT = 3;
    /**
     * 对异常信息进行统一处理，区分异步和同步请求，分别处理
     */
    public ModelAndView resolveException(HttpServletRequest request,
            HttpServletResponse response, Object handler, Exception ex) {
        boolean isajax = isAjax(request,response);
        Throwable deepestException = deepestException(ex);
        return processException(request, response, handler, deepestException, isajax);
    }
    /**
     * 判断当前请求是否为异步请求.
     */
    private boolean isAjax(HttpServletRequest request, HttpServletResponse response){
        return oConvertUtils.isNotEmpty(request.getHeader("X-Requested-With"));
    }
    /**
     * 获取最原始的异常出处，即最初抛出异常的地方
     */
    private Throwable deepestException(Throwable e){
        Throwable tmp = e;
        int breakPoint = 0;
        while(tmp.getCause()!=null){
            if(tmp.equals(tmp.getCause())){
                break;
            }
            tmp=tmp.getCause();
            breakPoint++;
            if(breakPoint>1000){
                break;
            }
        } 
        return tmp;
    }
    /**
     * 处理异常.
     * @param request
     * @param response
     * @param handler
     * @param deepestException
     * @param isajax
     * @return
     */
    private ModelAndView processException(HttpServletRequest request,
            HttpServletResponse response, Object handler,
            Throwable ex, boolean isajax) {
        //步骤一、异常信息记录到日志文件中.
        log.error("全局处理异常捕获:", ex);
        //步骤二、异常信息记录截取前50字符写入数据库中.
        logDb(ex);
        //步骤三、分普通请求和ajax请求分别处理.
        if(isajax){
            return processAjax(request,response,handler,ex);
        }else{
            return processNotAjax(request,response,handler,ex);
        }
    }
    /**
     * 异常信息记录截取前50字符写入数据库中
     * @param ex
     */
    private void logDb(Throwable ex) {
        //String exceptionMessage = getThrowableMessage(ex);
        String exceptionMessage = "错误异常: "+ex.getClass().getSimpleName()+",错误描述："+ex.getMessage();
        if(oConvertUtils.isNotEmpty(exceptionMessage)){
            if(exceptionMessage.length() > WIRTE_DB_MAX_LENGTH){
                exceptionMessage = exceptionMessage.substring(0,WIRTE_DB_MAX_LENGTH);
            }
        }
        systemService.addLog(exceptionMessage, LOG_LEVEL, LOG_OPT);
    }
    /**
     * ajax异常处理并返回.
     * @param request
     * @param response
     * @param handler
     * @param deepestException
     * @return
     */
    private ModelAndView processAjax(HttpServletRequest request,
            HttpServletResponse response, Object handler,
            Throwable deepestException){
        ModelAndView empty = new ModelAndView();
        //response.setContentType("application/json");
        response.setHeader("Cache-Control", "no-store");
        AjaxJson json = new AjaxJson();
        json.setSuccess(true);
        json.setMsg(deepestException.getMessage());
        PrintWriter pw = null;
        try {
            pw=response.getWriter();
            pw.write(JSONHelper.bean2json(json));
            pw.flush();
        } catch (IOException e) {
            e.printStackTrace();
        }finally{
            pw.close();
        }
        empty.clear();
        return empty;
    }
    /**
     * 普通页面异常处理并返回.
     * @param request
     * @param response
     * @param handler
     * @param deepestException
     * @return
     */
    private ModelAndView processNotAjax(HttpServletRequest request,
            HttpServletResponse response, Object handler, Throwable ex) {
        String exceptionMessage = getThrowableMessage(ex);
        Map<String, Object> model = new HashMap<String, Object>();
        model.put("exceptionMessage", exceptionMessage);
        model.put("ex", ex);
        return new ModelAndView("common/error", model);
    }
    /**
     * 返回错误信息字符串
     * 
     * @param ex
     *            Exception
     * @return 错误信息字符串
     */
    public String getThrowableMessage(Throwable ex) {
        StringWriter sw = new StringWriter();
        PrintWriter pw = new PrintWriter(sw);
        ex.printStackTrace(pw);
        return sw.toString();
    }
}。

<!-- 异常处理类 -->
    <bean id="exceptionHandler"
        class="org.jeecgframework.core.common.exception.GlobalExceptionResolver" />