关于Ajax中通过response在后台传递数据问题

var System = {   getHttpRequest: function(url, callback, options) {     if (url.length < 0) return;     var option = {       url: url,       type: "get",       dataType: "json",       cache: false,       timeout: 30000,       beforeSend: function(XHR) {       },       complete: function(XHR, textStatus) {         XHR.abort();       },       error: function(XMLHttpRequest, textStatus, errorThrown) {         //alert("网络连接不通，请稍后再试！");       },       success: function(data) {         callback(data, options);       }     };     if ( !! options) {       option = $.extend(option, options);     }     $.ajax(option);   } }; 

public String getRejectReason() throws Exception{     String rowId = getParameterAndPut("rowId",null,0).toString();     String jsonData = "";     if (StringUtils.isNotEmpty(rowId)) {       jsonData = newOwnerInfoService.getRejectReasonJsonData(rowId);     }     this.getResponse().setCharacterEncoding("utf-8");     this.getResponse().getWriter().write(jsonData);     return null; }