ajax和普通请求使用spring mvc在controller中的异常统一处理

（1）建共用的异常处理器 CustomExceptionResolver

packagecom.ggs.mstd.controller;

importjavax.servlet.http.HttpServletRequest;

importjavax.servlet.http.HttpServletResponse;

importorg.apache.ibatis.ognl.OgnlException;

importorg.springframework.stereotype.Controller;

importorg.springframework.web.bind.annotation.ExceptionHandler;

importorg.springframework.web.bind.annotation.ResponseBody;

importorg.springframework.web.servlet.ModelAndView;

importcom.ggs.mstd.CustomException.CustomException;

importcom.ggs.mstd.CustomException.RequestUtil;

importcom.ggs.mstd.CustomException.ResponseData;

@Controller

publicclassCustomExceptionResolver {

   

   /**@[e-mail]

     * 处理控制层所有异常.

     *@paramexception  未捕获的异常

     *@paramrequest  HttpServletRequest

     *@returnResponseData(BaseException 被处理) 或者 ModelAndView(其他 Exception ,500错误)

     */

   @ExceptionHandler(value = { Exception.class})

   public@ResponseBody  Object exceptionHandler(Exceptionexception, HttpServletRequestrequest, HttpServletResponseresponse) {

      /*判断请求类型是不是ajax的*/

     if(RequestUtil.isAjaxRequest(request)) {

          /*如果是Ajax请求将错误信息返回到ajaxdate*/

            Throwablethr= getRootCause(exception);

            ResponseDatares=newResponseData();

           if(thrinstanceofCustomException) {

              /*如果自定义的错误显示自定义的错误类型*/

              CustomExceptionbe= (CustomException)thr;

              res.findMessage(be.getCode());

              res.setCode(be.getCode());

               res.setMessage(be.getMessage());

            }else{ 

              /*如果不是自定义的错误显示系统性错误或同一错误*/

                 res.findMessage(ResponseData.SYSTEM_EXCEPTION);

               res.setMessage(thr.getMessage());

            }

           returnres;     

        }else{

          /*如果不是Ajax的重从定向到错误界面*/

           returnnewModelAndView("redirect:/categoryAttribute");

        }

    }

   privateThrowable getRootCause(Throwablethrowable) {

       while(throwable.getCause() !=null) {

           throwable=throwable.getCause();

        }

       if(throwableinstanceofOgnlException && ((OgnlException)throwable).getReason() !=null) {

           returngetRootCause(((OgnlException)throwable).getReason());

        }

       returnthrowable;

    }

}

（2）建立一个终态的类RequestUtil 判断请求类型

packagecom.ggs.mstd.CustomException;

importjavax.servlet.http.Cookie;

importjavax.servlet.http.HttpServletRequest;

/**

 *@authorwenfei.fang

 *

 *         2016年11月11日

 */

publicfinalclassRequestUtil {

   publicstaticfinalStringX_REQUESTED_WIDTH="X-Requested-With";

   publicstaticfinalStringXML_HTTP_REQUEST="XMLHttpRequest";

   privateRequestUtil() {

    }

   /**

     * 判断是否ajax请求.

     * 可以看到Ajax请求多了个 x-requested-with ，可以利用它，

     * request.getHeader("x-requested-with"); 为 null，则为传统同步请求，为 XMLHttpRequest，则为Ajax异步请求。

     *@paramrequest  HttpServletRequest

     *@return是否ajax请求.

     */

   publicstaticbooleanisAjaxRequest(HttpServletRequestrequest) {

        Stringxr=request.getHeader(X_REQUESTED_WIDTH);

       return(xr!=null&&XML_HTTP_REQUEST.equalsIgnoreCase(xr));

    }

   publicstaticString getCookieValue(HttpServletRequestrequest, Stringname) {

        Cookie[]cookies=request.getCookies();

       if(cookies!=null) {

           for(Cookiecookie:cookies) {

                StringcookieName=cookie.getName();

               if(cookieName.equals(name)) {

                   returncookie.getValue();

                }

            }

        }

       returnnull;

    }

}

（3）建立一个类 继承 Exception

publicabstractclassCustomExceptionextendsException {

   privatestaticfinallongserialVersionUID= 1L;

   // e.g. ORDER_FROZEN

   privateStringcode;

   privateStringdescriptionKey;

   privateObject[]parameters;

   /**

     * 不应该直接实例化,应该定义子类.

     *

     *@paramcode

     *            异常 code,通常与模块 CODE 对应

     *@paramdescriptionKey

     *            异常消息代码,系统描述中定义

     *@paramparameters

     *            如果没有参数,可以传 null

     */

   protectedCustomException(Stringcode, StringdescriptionKey, Object[]parameters) {

       super(descriptionKey);

       this.code=code;

       this.descriptionKey=descriptionKey;

       this.parameters=parameters;

    }

   publicString getCode() {

       returncode;

    }

   publicString getDescriptionKey() {

       returndescriptionKey;

    }

   publicObject[] getParameters() {

       returnparameters;

    }

   publicvoidsetCode(Stringcode) {

       this.code=code;

    }

   publicvoidsetDescriptionKey(StringdescriptionKey) {

       this.descriptionKey=descriptionKey;

    }

   publicvoidsetParameters(Object[]parameters) {

       this.parameters=parameters;

    }

}

（4）错误处理类

/**

 * 数据返回对象.

 *

 *@[e-mail]

 */

publicclassResponseData{

     

     publicstaticfinalStringSYSTEM_EXCEPTION="Please contact the administrator.";

     publicstaticfinalStringMSG_ERROR_APPROVE_COMMENTS="msg error approve comments";

     

     public voidfindMessage(Stringcode){

          this.message=code==null?SYSTEM_EXCEPTION:code;

     }

     

     

   // 返回状态编码

 

   privateStringcode;

   // 返回信息

   

     privateStringmessage;

   publicString getCode() {

          returncode;

     }

     publicvoidsetCode(Stringcode) {

          this.code=code;

     }

     publicString getMessage() {

          returnmessage;

     }

     publicvoidsetMessage(Stringmessage) {

          this.message=message;

     }

 

}

（5）Controller继承CustomExceptionResolver错误处理

@Controller

public class MegaFileReportController extends CustomExceptionResolver{

   @RequestMapping(value = "/api/megaFile/e")

public @ResponseBody String e(@RequestParam Map<String, Object> params) {

int m=1/0;

return null;

}

}