var oldElement = jQuery('#' + fileElementId); 
var newElement = jQuery(oldElement).clone(); 
jQuery(oldElement).attr('id', fileId); 
jQuery(oldElement).before(newElement); 
jQuery(oldElement).appendTo(form); 

if(typeof(fileElementId) == 'string'){ 
 fileElementId = [fileElementId]; 
} 
for(var i in fileElementId){ 
 var oldElement = jQuery('#' + fileElementId[i]); 
 var newElement = jQuery(oldElement).clone(); 
 jQuery(oldElement).attr('id', fileId); 
 jQuery(oldElement).before(newElement); 
 jQuery(oldElement).appendTo(form); 
} 

$.ajaxFileUpload({ 
 url:'/ajax.php', 
 fileElementId:['id1','id2']//原先是fileElementId:'id' 只能上传一个 
}); 

if(typeof(fileElementId) == 'string'){ 
   fileElementId = [fileElementId]; 
  } 
  for(var i in fileElementId){ 
   //按name取值 
   var oldElement = jQuery("input[name="+fileElementId[i]+"]"); 
   oldElement.each(function() { 
    var newElement = jQuery($(this)).clone(); 
    jQuery(oldElement).attr('id', fileId); 
    jQuery(oldElement).before(newElement); 
    jQuery(oldElement).appendTo(form); 
   }); 
  } 

<div> 
    <img id="loading" src="scripts/ajaxFileUploader/loading.gif" style="display:none;"> 
    
     <table cellpadding="0" cellspacing="0" class="tableForm" id="calculation_model"> 
      <thead> 
      <tr> 
       <th>多组多个文件</th> 
      </tr> 
      </thead> 
      <tbody> 
      <tr> 
       <td>第一组</td> 
       <td>第二组</td> 
      </tr> 
      <tr> 
       <td><input type="file" name="gridDoc" class="input"></td> 
       <td><input type="file" name="caseDoc" class="input"></td> 
      </tr> 
      </tbody> 
      <tfoot> 
      <tr> 
       <td><button class="button" id="up1">Upload</button></td> 
       <td><button class="button" id="addInput" >添加一组</button></td> 
      </tr> 
      </tfoot> 
     </table> 
   </div> 

/** 
 * Created with IntelliJ IDEA. 
 * User: Administrator 
 * Date: 13-7-3 
 * Time: 上午9:20 
 * To change this template use File | Settings | File Templates. 
 */ 
$(document).ready(function () { 
 $("#up1").click(function(){ 
  var temp = ["gridDoc","caseDoc"]; 
  ajaxFileUpload(temp); 
 }); 
 
 $("#addInput").click(function(){ 
  addInputFile(); 
 }); 
 
}); 
 
//动态添加一组文件 
function addInputFile(){ 
 $("#calculation_model").append(" <tr>"+ 
  "<td><input type='file' name='gridDoc' class='input'></td> "+ 
  "<td><input type='file' name='caseDoc' class='input'></td> "+ 
  "</tr>"); 
} 
 
 
//直接使用下载下来的文件里的demo代码 
function ajaxFileUpload(id) 
{ 
 //starting setting some animation when the ajax starts and completes 
 $("#loading").ajaxStart(function(){ 
   $(this).show(); 
  }).ajaxComplete(function(){ 
   $(this).hide(); 
  }); 
 
 /* 
  prepareing ajax file upload 
  url: the url of script file handling the uploaded files 
  fileElementId: the file type of input element id and it will be the index of $_FILES Array() 
  dataType: it support json, xml 
  secureuri:use secure protocol 
  success: call back function when the ajax complete 
  error: callback function when the ajax failed 
 
  */ 
 $.ajaxFileUpload({ 
   url:'upload.action', 
   //secureuri:false, 
   fileElementId:id, 
   dataType: 'json' 
  } 
 ) 
 
 return false; 
 
} 

package com.ssy.action; 
 
import com.opensymphony.xwork2.ActionSupport; 
import org.apache.commons.io.FileUtils; 
import org.apache.struts2.util.ServletContextAware; 
 
import javax.servlet.ServletContext; 
import java.io.*; 
import java.text.SimpleDateFormat; 
import java.util.Date; 
import java.util.Random; 
 
/** 
 * Created with IntelliJ IDEA. 
 * User: Administrator 
 * Date: 13-7-2 
 * Time: 下午4:08 
 * To change this template use File | Settings | File Templates. 
 */ 
public class Fileupload extends ActionSupport implements ServletContextAware { 
 private File[] gridDoc,caseDoc; 
 private String[] gridDocFileName,caseDocFileName; 
 
 private ServletContext context; 
 
  
 
 public String execute(){ 
  for (int i = 0;i<gridDocFileName.length;i++) { 
   System.out.println(gridDocFileName[i]); 
  } 
  for (int i = 0;i<caseDocFileName.length;i++) { 
   System.out.println(caseDocFileName[i]); 
  } 
 
 
  //System.out.println(doc1FileName); 
  //System.out.println(doc2FileName); 
  String targetDirectory = context.getRealPath("/uploadFile"); 
 
  /* 
   *这里我只取得 第一组的文件进行上传，第二组的类似 
  */ 
 try{ 
   for (int i = 0; i < gridDoc.length; i++) { 
    String targetFileName = generateFileName(gridDocFileName[i]); 
    File target = new File(targetDirectory, targetFileName); 
    FileUtils.copyFile(gridDoc[i], target); 
   } 
  }catch (Exception e){ 
   e.printStackTrace(); 
  }  
 
  return SUCCESS; 
 } 
 
 public File[] getGridDoc() { 
  return gridDoc; 
 } 
 
 public void setGridDoc(File[] gridDoc) { 
  this.gridDoc = gridDoc; 
 } 
 
 public File[] getCaseDoc() { 
  return caseDoc; 
 } 
 
 public void setCaseDoc(File[] caseDoc) { 
  this.caseDoc = caseDoc; 
 } 
 
 public String[] getGridDocFileName() { 
  return gridDocFileName; 
 } 
 
 public void setGridDocFileName(String[] gridDocFileName) { 
  this.gridDocFileName = gridDocFileName; 
 } 
 
 public String[] getCaseDocFileName() { 
  return caseDocFileName; 
 } 
 
 public void setCaseDocFileName(String[] caseDocFileName) { 
  this.caseDocFileName = caseDocFileName; 
 } 
 
 /** 
  * 用日期和随机数格式化文件名避免冲突 
  * @param fileName 
  * @return 
  */ 
 private String generateFileName(String fileName) { 
  System.out.println(fileName); 
  SimpleDateFormat sf = new SimpleDateFormat("yyMMddHHmmss"); 
  String formatDate = sf.format(new Date()); 
  int random = new Random().nextInt(10000); 
  int position = fileName.lastIndexOf("."); 
  String extension = fileName.substring(position); 
  return formatDate + random + extension; 
 } 
 
}