多文件上传,同时改名，并生成缩略图

html:

<script>
function changeFileInput(){
	
	var num=$("fileSelect").value;
	while($("files").childNodes.length>0){
		$("files").removeChild($("files").childNodes[0]);
	}
	for(var i=0;i<num;i++){
		filediv=document.createElement("div");
		file=document.createElement("input");
		file.type="file";
		file.name="file"+i;
		file.size="50";
		filediv.appendChild(file);
		$("files").appendChild(filediv);
	}
}
</script>
<td class="td_right">
                        	<div id="files">
                            	<html:file property="file" value="浏览..." size="50" onkeypress="event.returnValue=false;" ></html:file><br />
                            </div>
						    <html:select property="fileSelect" size="1" onchange="changeFileInput()">
								<html:option value="1">1</html:option>
								<html:option value="2">2</html:option>
								<html:option value="3">3</html:option>
								<html:option value="4">4</html:option>
								<html:option value="5">5</html:option>
						    </html:select>
                            <input title="上传图片" class="button_y" name="upload" onclick=""  type="submit" value="上传图片"><span class="xing">图片小于65k</span>
                          	<html:errors/>
							<a href="ledger.portal?action=download&id=fieldId">下载</a>
                            <input title="图片管理" class="button_y" name="imageManage" onclick=""  type="submit" value="图片管理">
                        </td>
                    </tr>

java:

if(request.getParameter("upload")!=null){
				System.out.println("---------------------upload---------------------");
				
//				struts多文件上传，JSP中<html:file>的property必须不一样！
			    System.out.println("----------多文件上传开始-------------");
			    String realPath=this.getServlet().getServletContext().getRealPath("/");
				if(realPath.endsWith("./")){//linux外网访问多了./ why???
					realPath=realPath.substring(0, realPath.length()-2);
				}
			    String uploadPath = realPath + "UserFiles"+File.separator+"Image"; //上传文件存放目录 
				System.out.println("loadpath="+uploadPath);
				List<String> list = new ArrayList<String>();
				list.add("jpg");
		        list.add("jpeg");
		        list.add("gif");
		        list.add("bmp");
		        list.add("png");
				Hashtable hash=ledgerForm.getMultipartRequestHandler().getFileElements();//获得FormFile的数目,注意JSP中<html:file>的property
				System.out.println("hash.size="+hash.size());
				int i=0;
				for (Enumeration e = hash.keys(); e.hasMoreElements(); ) { 
		            String key = (String) e.nextElement();
		            FormFile formfile = (FormFile) hash.get(key);
		            String fileName = formfile.getFileName().trim(); //文件名
		            String contentType=formfile.getContentType();
					long size=formfile.getFileSize();
		            String extName=fileName.substring(fileName.lastIndexOf(".")+1).toLowerCase();
		            if(fileName==null||fileName.equals("")){//防没有文件时上传垃圾文件的bug
		            	System.out.println("文件名为空，跳出循环！");
						initNewsList(mapping,ledgerForm,request,response);
						return mapping.findForward("management");
					}
		            if(!list.contains(extName)){
			        	errors.add("error.image.contentType", new ActionMessage("error.image.contentType"));
			        	this.saveErrors(request, errors);
//			        	initNewsList(mapping,ledgerForm,request,response);
//			        	return mapping.findForward("management");
		            	System.out.println("上传文件中有不符合扩展名要求的文件("+fileName+"),继续下一个上传文件...");
		            	continue;//扩展名不符合要求就跳过他
			        }
		            if(size>=1024*65){//65k
						errors.add("error.image.size", new ActionMessage("error.image.size"));
						this.saveErrors(request, errors);
//						initNewsList(mapping,ledgerForm,request,response);
//						return mapping.findForward("management");
		            	System.out.println("上传文件中有不符合大小要求的文件("+fileName+"),继续下一个上传文件...");
		            	continue;//文件大小不符合要求就跳过他
					}
		            Date date = new Date(System.currentTimeMillis()); 
					SimpleDateFormat format = new SimpleDateFormat("yyyyMMddHHmmss");
					String newFileName= format.format(date)+"_"+i+"."+extName;
					i++;
	                if (!"".equals(fileName)) { //不同的浏览器传上的文件名可能有区别，有的是全路径的 
	                    InputStream is = formfile.getInputStream(); 
	                    OutputStream os = new FileOutputStream(uploadPath+File.separator+newFileName); 
	                    int bytesRead = 0; 
	                    byte[] buffer = new byte[8192]; 
	                    while ((bytesRead = is.read(buffer, 0, 8192)) != -1) { 
	                        os.write(buffer, 0, bytesRead); 
	                    } 
	                    os.close(); 
	                    is.close(); 
	                }
	                ////////////////////////////////////
	                System.out.println("--------------图片放大缩小开始----------------");
	               
	                String tempPath = realPath + "UserFiles"+File.separator+"temp"; //上传文件存放目录 
	                int w=96;
	                int h=-20;
	                if(extName.equals("gif")){//解决生成gif图像时大小为0的bug
	                	extName="png";
	                }
	                String oldPath=uploadPath+File.separator+newFileName;//Image文件夹
	                String newPath=tempPath+File.separator+newFileName;//temp文件夹
	                try{
	                	Util.resize(oldPath, w, h, newPath, extName);// 图片放大缩小
	                }catch (Exception ex) {
						// TODO: handle exception
	                	System.out.println("出现异常时将原图直接写入temp文件夹，不要缩略了");
	                	InputStream is = formfile.getInputStream();
	                    OutputStream os = new FileOutputStream(newPath); 
	                    int bytesRead = 0; 
	                    byte[] buffer = new byte[8192]; 
	                    while ((bytesRead = is.read(buffer, 0, 8192)) != -1) { 
	                        os.write(buffer, 0, bytesRead); 
	                    } 
	                    os.close(); 
	                    is.close(); 
	                    Util.imageWidth=96;//异常时,当作96像素
	                    Util.imageHeight=96;
					}
	                System.out.println("--------------图片放大缩小结束----------------");
	                ///////////////////////////////////////////////////
	                System.out.println("--------------保存缩略图/原图开始----------------");
	                ImageManage imageManage=new ImageManage();
	                imageManage.setDate(Util.getCurrentDate("yyyyMMddhhmmss"));
	                imageManage.setImageName(newFileName);//缩略图名=原图名，只是文件夹不一样
	                imageManage.setUser(Util.userName);
	                imageManage.setRemark("0");
	                imageManage.setWidth(Util.imageWidth);//保存图片宽高
	                imageManage.setHeight(Util.imageHeight);
	                this.getLedgerService().save(imageManage);
	                System.out.println("--------------保存缩略图/原图结束----------------");
				}
//				hash.clear();
			    System.out.println("----------多文件上传结束-------------");
				
			    ledgerForm.setFileSelect("1");
				initNewsList(mapping,ledgerForm,request,response);
				return mapping.findForward("management");
			}