extjs的分页grid整体导出为excecl

我通过extjs和struts,将grid数据导出为excel,但因为grid是分页的,我想将所有页数据整体导出为excel,该如何修改?代码如下:
extjs: function downloadViewData(grid){   
var vExportContent = grid.getExcelXml(); 
if (Ext.isIE6 || Ext.isIE7 || Ext.isSafari || Ext.isSafari2 || Ext.isSafari3) { 
  var fd=Ext.get('frmDummy');               
  if (!fd) {                   
  fd=Ext.DomHelper.append(Ext.getBody(),                   
  {                   
  tag:'form',                   
  method:'post',                   
  id:'frmDummy',                   
  action:'exportexcel.jsp',                    
  target:'_blank',                   
  name:'frmDummy',                   
  cls:'x-hidden',                   
  cn:[                       
  {                       
  tag:'input',                       
  name:'exportContent',                       
  id:'exportContent',                       
  type:'hidden'                       
  }                   
  ]                   
  }
  ,true);               
  }               
  fd.child('#exportContent').set({value:vExportContent});               
  fd.dom.submit();           
  } else {               
  document.location = 'data:application/vnd.ms-excel;base64,'+Base64.encode(vExportContent);           
  } 
}
jsp:<%@ page language="java" pageEncoding="UTF-8"%>
<% 
request.setCharacterEncoding("UTF-8");
response.setHeader("Content-Type","application/force-download");
response.setHeader("Content-Type","application/vnd.ms-excel");
response.setHeader("Content-Disposition","attachment;filename=export.xls");
out.print(request.getParameter("exportContent")); 
%>