1、先创建一个简单的web项目upload (如图1-1)

2、插件的准备

(1)、去uploadify的官网下载一个uploadify插件,然后解压新建个js文件夹放进去(这个不强求，只要路径对了就可以)

(2)、准备所需要的后端处理上传文件的jar包:commons-fileupload-1.2.1.jar

3、新建一个JSP即index.jsp +servlet即UploadServlet.java

图1-1

4、花几分钟对这些简单的配置完成后就可以看看index.jsp与UoloadServlet.java

(1)index.jsp

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
 
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
    <head>
        <base href="<%=basePath%>">
        <title>My JSP 'index.jsp' starting page</title>
        <meta http-equiv="pragma" content="no-cache">
        <meta http-equiv="cache-control" content="no-cache">
        <meta http-equiv="expires" content="0">
        <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
        <meta http-equiv="description" content="This is my page">
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
        <link rel="stylesheet" type="text/css" href="css/uploadify.css">
        <script src="<%=basePath%>js/uploadify/jquery-1.4.2.min.js"></script>
        <script src="<%=basePath%>js/uploadify/jquery.uploadify.v2.1.4.min.js"></script>
        <script src="<%=basePath%>js/uploadify/swfobject.js"></script>
    </head>
    <body>
        This is my JSP page.
        <br>
        <table class="stable tp0" cellSpacing="0" cellPadding="0" border="0">
            <tr>
                <td width="15%" align="left" colspan="4" style="padding-left: 158px">
  
                    <input type="hidden" id="fileSize" value="0" />
  
                    <div id="custom-queue"></div> 附件：<input id="uploadify" type="file"
                    name="Filedata" />
                </td>
            </tr>
        </table>
    </body>
    <script type="text/javascript">
  $(document).ready(function(){
   
      $(document).ready(function () {
            $("#uploadify").uploadify({
                'uploader': '<%=basePath%>js/uploadify/uploadify.swf',
                'script': '<%=basePath%>servlet/UploadServlet',
                'cancelImg': '<%=basePath%>js/uploadify/cancel.png',
                'folder': 'upload',
                'queueID' : 'custom-queue',
                'auto':true,
                'multi':true,
                'fileDataName':'Filedata',
                 'onCancel' : function(file) {  
                },
                'onUploadError' : function(file, errorCode, errorMsg, errorString) {  
                    alert(456);  
                }
            });
        });
  });
 
  </script>
</html>

(2).UoloadServlet.java

package coms;

import java.io.File;
import java.io.IOException;
import java.util.Iterator;
import java.util.List;
import java.util.UUID;

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

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;

public class UploadServlet extends HttpServlet {

    @Override
    protected void doPost(HttpServletRequest request,
            HttpServletResponse response) throws ServletException, IOException {
        String savePath = this.getServletConfig().getServletContext()
                .getRealPath("");
        //保存文件的路径
        savePath = savePath + "/upload/";
        File f1 = new File(savePath);
        System.out.println(savePath);
        //如果文件不存在,就新建一个
        if (!f1.exists()) {
            f1.mkdirs();
        }
        //这个是文件上传需要的类,具体去百度看看,现在只管使用就好
        DiskFileItemFactory fac = new DiskFileItemFactory();
        ServletFileUpload upload = new ServletFileUpload(fac);
        upload.setHeaderEncoding("utf-8");
        List fileList = null;
        try {
            fileList = upload.parseRequest(request);
        } catch (FileUploadException ex) {
            return;
        }
        //迭代器,搜索前端发送过来的文件
        Iterator<FileItem> it = fileList.iterator();
        String name = "";
        String extName = "";
        while (it.hasNext()) {
            FileItem item = it.next();
            //判断该表单项是否是普通类型
            if (!item.isFormField()) {
                name = item.getName();
                long size = item.getSize();
                String type = item.getContentType();
                System.out.println(size + " " + type);
                if (name == null || name.trim().equals("")) {
                    continue;
                }
                // 扩展名格式： extName就是文件的后缀,例如 .txt
                if (name.lastIndexOf(".") >= 0) {
                    extName = name.substring(name.lastIndexOf("."));
                }
                File file = null;
                do {
                    // 生成文件名：
                    name = UUID.randomUUID().toString();
                    file = new File(savePath + name + extName);
                } while (file.exists());
                File saveFile = new File(savePath + name + extName);
                try {
                    item.write(saveFile);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        }
        response.getWriter().print(name + extName);
    }

}

对于jsp与java没有好好说明,如果不懂可以私聊我,其实花了很多个小时才使用这个uploadify,主要是因为以为上传只要uploadify插件就可以，原来还需要:commons-fileupload-1.2.1.jar ,我是一个喜欢分享的人,希望每个人有能力都能写写博客,让更多人好好学习,觉得不错就点一下推荐，让更多人快速掌握。

5.鼓励:觉得写得有帮助就支付宝扫一下吧，对你没有损失，也给我动力