java uploadify 示例

import javax.servlet.*; import javax.servlet.http.*; import java.io.*; import java.util.*; import org.apache.commons.fileupload.FileItem; import org.apache.commons.fileupload.FileUploadException; import org.apache.commons.fileupload.disk.DiskFileItemFactory; import org.apache.commons.fileupload.servlet.ServletFileUpload; /** 文件上传 步骤: (1) */ public class ProcessUpload extends HttpServlet { public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { /**/ System.out.println("I am a serlvet to process upload!!!"); request.setCharacterEncoding( "UTF-8" ); // 从request中取时, 以UTF-8编码解析 // 工厂, DiskFileItemFactory diskFileItemFactory = new DiskFileItemFactory(); // 获取上传文件存放的 目录 , 无则创建 String path = request.getRealPath( "/upload" ); System.out.println("path : " + path); new java.io.File( path ).mkdir(); /** * 原理 它是先存到 暂时存储室，然后在真正写到 对应目录的硬盘上， * 按理来说 当上传一个文件时，其实是上传了两份，第一个是以 .tem 格式的 * 然后再将其真正写到 对应目录的硬盘上 */ diskFileItemFactory.setRepository( new File( path ) ); //设置 缓存的大小，当上传文件的容量超过该缓存时，直接放到 暂时存储室 diskFileItemFactory.setSizeThreshold( 1024*1024 ); ServletFileUpload upload = new ServletFileUpload(diskFileItemFactory); try { // 可上传多个文件 @SuppressWarnings("unchecked") List<FileItem> list = (List<FileItem>) upload.parseRequest( request ); for (FileItem item : list ) { // 获取 提交表单的 属性名 String name = item.getFieldName(); // 字符串类 属性 if ( item.isFormField() ) { String value = item.getString(); System.out.println(name + "=" + value); } // 二进制类 else { // 获取上传文件的名字 String value = item.getName(); // 1,获取路径 int start = value.lastIndexOf( "\\" );// 2,索引到最后一个反斜杠 String filename = value.substring( start+1 );//3, 截取(+1是去掉反斜杠) System.out.println( name + "=" + value ); File file = null; do { // 生成文件名 start = filename.lastIndexOf( "." ); // 索引到最后一个点 filename = filename.substring( 0, start ) // 不含扩展名的文件 + UUID.randomUUID().toString() // 随机数 + filename.substring( start ); // 扩展名 file = new File(path, filename); } while (file.exists()); System.out.println( "filename=" + filename ); // 写到磁盘上去 item.write( file ); System.out.println( "the upload file's size:" + item.getSize() ); } } } catch (Exception e) { e.printStackTrace(); } } // ------------------- public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { this.doPost(request, response); } public static void main(String[] args) { System.out.println( "I am a serlvet to process upload!" ); } }