上传页面jsp：

<script type="text/javascript">

      function addTR(){
         var tab = document.getElementById("tab");
         var newRow = tab.insertRow(tab.rows.length);
         newRow.insertCell(0).innerHTML="<input type=\"file\" name=\"file\"/>";
      }
     
      function delRow(){
         var tab = document.getElementById("tab");
         if(tab.rows.length>3){
            tab.deleteRow(tab.rows.length-1);
         }else{
            alert("至少保留二行！");
         }
      }
        
  </script>
 </head>

 <body>

  <center>
   <form action="multiupload.action" method="post"
    enctype="multipart/form-data">
    <table cellpadding="0" cellspacing="0" style="width: 500px;"
     id="tab">
     <tr>
      <td>
       <input type="button" value="增加上传文件" />
       <input type="button" value="减少" />
       <input type="reset" value="重置" />
       <input type="submit" value="上传" />
      </td>
     </tr>
     <tr>
      <td>
       <input type="file" name="file" />
      </td>
     </tr>
     <tr>
      <td>
       <input type="file" name="file" />
      </td>
     </tr>
    </table>
   </form>
  </center>
 </body>

成功页面：

<body>

  <c:forEach items="${fileFileName}" var="file" varStatus="status">
  文件上传成功!!!
  <hr>
  
  <br />
  文件名称：${upload.fileFileName[status.index]}
  <br />
  文件类型：${upload.fileContentType[status.index]}
  <br />
  </c:forEach>
 </body>

web.xml://配置struts-clean，避免第一次上传取不到文件

<filter>

  <filter-name>struts-cleanup</filter-name>
  <filter-class>org.apache.struts2.dispatcher.ActionContextCleanUp</filter-class>
 </filter>

 <filter-mapping>

  <filter-name>struts-cleanup</filter-name>
  <url-pattern>/*</url-pattern>
 </filter-mapping>

struts.xml

<struts>

 <constant name="struts.i18n.encoding" value="utf-8"></constant>
 <package name="default" namespace="/" extends="struts-default">
  <action name="product" class="com.tudou.struts.action.ProductAction">
  </action>
  <action name="upload" class="com.tudou.struts.action.FileUpLoadAction">
   <param name="savePath">/uploadfiles</param>
   <result name="success">/fileSuccess.jsp</result>
  </action>
  <action name="multiupload" class="com.tudou.struts.action.MultiFileUpLoadAction">
   <param name="savePath">/uploadfiles</param>
   <result name="success">/success.jsp</result>
  </action>
 </package>
 <package name="myPackage" namespace="/" extends="struts-default">
  <action name="login" class="com.tudou.struts.action.LoginAction">
   <result name="input">/login.jsp</result>
   <result name="index">/index.jsp</result>
  </action>
 </package>

action：

package com.tudou.struts.action;

import java.io.File;

import java.io.FileInputStream;
import java.io.FileOutputStream;

import org.apache.struts2.ServletActionContext;

import com.opensymphony.xwork2.ActionContext;

public class MultiFileUpLoadAction {

 // private String[] title; // 文件标题
 private File[] file; // 文件域
 private String fileContentType[]; // 文件类型
 private String[] fileFileName; // 文件名
 private String savePath; // 上传地址

 public void setSavePath(String savePath) {

  this.savePath = savePath;
 }

 // public String[] getTitle() {

 // return title;
 // }
 //
 // public void setTitle(String[] title) {
 // this.title = title;
 // }

 public File[] getFile() {

  return file;
 }

 public void setFile(File[] file) {

  this.file = file;
 }

 public String[] getFileContentType() {

  return fileContentType;
 }

 public void setFileContentType(String[] fileContentType) {

  this.fileContentType = fileContentType;
 }

 public String[] getFileFileName() {

  return fileFileName;
 }

 public void setFileFileName(String[] fileFileName) {

  this.fileFileName = fileFileName;
 }

 // 返回保存地址

 public String getSavePath() throws Exception {
  return ServletActionContext.getRequest().getRealPath(savePath);
 }

 public String execute() throws Exception {

  for (int i = 0; i < file.length; i++) {
   // 以服务器的文件保存地址的原文件名建立上传文件输出流
   FileOutputStream fos = new FileOutputStream(this.getSavePath()
     + "\\" + this.getFileFileName()[i]);
   // 以上传文件建立文件输入流
   FileInputStream fis = new FileInputStream(this.getFile()[i]);
   // 将上传文件内容写入服务器
   byte[] b = new byte[1024];
   int len = 0;
   while ((len = fis.read(b)) > 0) {
    fos.write(b, 0, len);
   }
  }
  ActionContext.getContext().put("upload", this);
  return "success";
 }
}