private  List  myFiles;

        public  MultiUploadForm(){
                myFiles  =  new  ArrayList();
                myFiles.add(new  UploadFile());
        }
        public  List  getMyFiles()  {
                return  myFiles;
        }

    //注意这个方法的定义  不加中间的循环是会出错的

      public  UploadFile  getUploadFile(int  index){
                int  size  =  myFiles.size();
                if(index>size-1){
                 for(int i=0;i<index-size+1;i++){
                        myFiles.add(new  UploadFile());
                 }
                }
                return  (UploadFile)myFiles.get(index);
        }
        public  void  setMyFiles(List  myFiles)  {
                this.myFiles  =  myFiles;
        }

    }

最后是action

    package com.hb.struts.action;

    import java.io.IOException;
    import java.io.PrintWriter;
    import java.util.List;

    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;

    import org.apache.struts.action.Action;
    import org.apache.struts.action.ActionForm;
    import org.apache.struts.action.ActionForward;
    import org.apache.struts.action.ActionMapping;
    import org.apache.struts.upload.FormFile;

    public class MultiUploadAction extends Action {
     public ActionForward execute(ActionMapping mapping, ActionForm form,
       HttpServletRequest request, HttpServletResponse response) {
      MultiUploadForm multiUploadForm = (MultiUploadForm) form;

      List myFiles = multiUploadForm.getMyFiles();
      String fileStr = "";
      for (int i = 0; i < myFiles.size(); i++) {
       UploadFile uploadFile = (UploadFile) myFiles.get(i);
       FormFile file = uploadFile.getFile();

       if (file == null) {
        System.out.println("file  is  null");
       } else {

        // 能运行到这里，就可以使用单个文件上传的方法进行上传了。循环而已
        System.out.println("filename>>>>>>>>>>" + file.getFileName());
        System.out.println("file  size>>>>>>>>>>" + file.getFileSize());