Struts 2 怎么返回一个字符串给jsp页面啊?报错

需求是 java调用存储过程 存储如果报错的话我在java中写了个字符串 怎么传给前台然后弹框

这是action 

    public String personExtractInfo() throws IOException {
//    	extractData.setExactType("2");
    	HttpServletResponse response = this.getResponse();
    	try {
    		if (extractData.getExactType().equals("1")) {
    			error= informationManageService.getExtractInfo2(extractData);
    			error= informationManageService.getExtractInfo3(extractData);
    			error= informationManageService.getExtractInfo3s(extractData);
    			error= informationManageService.getExtractInfo4(extractData);
    			error= informationManageService.getExtractInfo5(extractData);
    			error= informationManageService.getExtractInfo6(extractData);
    			error= informationManageService.getExtractInfo7(extractData);
        		error= informationManageService.getExtractInfo8(extractData);
    		}
        	if (extractData.getExactType().equals("2")) {
        		error= informationManageService.getExtractInfo2(extractData);
    		}
        	if (extractData.getExactType().equals("3")) {
        		error= informationManageService.getExtractInfo3(extractData);
    		}
        	if (extractData.getExactType().equals("3")) {
        		error= informationManageService.getExtractInfo3s(extractData);
    		}
        	if (extractData.getExactType().equals("4")) {
        		error= informationManageService.getExtractInfo4(extractData);
    		}
        	if (extractData.getExactType().equals("5")) {
        		error= informationManageService.getExtractInfo5(extractData);
    		}
        	if (extractData.getExactType().equals("6")) {
        		error= informationManageService.getExtractInfo6(extractData);
    		}
        	if (extractData.getExactType().equals("7")) {
        		error= informationManageService.getExtractInfo7(extractData);
        		error= informationManageService.getExtractInfo8(extractData);
    		}
		} catch (Exception e) {
			e.printStackTrace();
			error="导入失败";
		}
    		error="导入成功";
    	   
    	   return "success";
      }

这是 配置

 <action name="if_" class="informationManageAction" method="personExtractInfo">
                                     <result type="json">
                                               <param name="root">erro</param>
                                     </result>
                            </action>

这是 jsp

    function login() {
            $.ajax({
                type: "POST",//方法类型
                dataType: "text",//预期服务器返回的数据类型
                url: "${ctx}/informationManage/if_personExtractInfo.do" ,//url
                data: $('#form1').serialize(),
                success: function (data) {
                	  if(data=="导入失败"){
				alert("23213");
                } 
                },
                error : function() {
                	alert("222")
                }
            });
        } 

erro 这个变量有setget方法