资源都是来自网上。本实例将展示使用Flex和java servlet上传文件。

事前准备就是到http://commons.apache.org 下载common-fileupload-1.1.1.jar以及common-io-1.2.jar两个包。

前台Flex代码：

Xml代码  

import flash.net.FileReference;

import mx.controls.Alert;

import mx.events.CloseEvent;

import flash.events.*;

private var file: FileReference;

private function init(): void{

Security.allowDomain("*");

file = new FileReference();

file.addEventListener(ProgressEvent.PROGRESS, onProgress);

file.addEventListener(Event.SELECT, onSelect);

file.addEventListener(Event.COMPLETE, completeHandle);

}

private function completeHandle(event:Event):void{

Alert.show("恭喜你，上传成功");

}

private function upload(): void{

var imageTypes:FileFilter = new FileFilter("Images (*.jpg, *.jpeg, *.png)", "*.jpg;*.jpeg;*.png");

var allTypes:Array = new Array(imageTypes);

file.browse(allTypes);

file.browse();

}

private function onSelect(e: Event): void{

Alert.show("上传 " + file.name + " (共 "+Math.round(file.size)+" 字节)?",

"确认上传",

Alert.YES|Alert.NO,

null,

proceedWithUpload);

}

private function onProgress(e: ProgressEvent): void{

lbProgress.text = " 已上传 " + e.bytesLoaded

+ " 字节，共 " + e.bytesTotal + " 字节";

var proc: uint = e.bytesLoaded / e.bytesTotal * 100;

bar.setProgress(proc, 100);

bar.label= "当前进度: " + " " + proc + "%";

}

private function proceedWithUpload(e: CloseEvent): void{

if (e.detail == Alert.YES){

var request: URLRequest = new URLRequest("http://localhost:8080/FileUploaded/FileUploaded");

try {

file.upload(request);

} catch (error:Error) {

trace("上传失败");

}

}

}

]]>

minimum="0"visible="true"maximum="100"label="当前进度: 0%"

direction="right"mode="manual"width="200"/>

接下来写的是Java Servlet:

package upload;

import java.io.File;

import java.io.IOException;

import java.io.PrintWriter;

import java.util.Iterator;

import java.util.List;

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;

/**

*

* @author crystal

*/

public class FileUploaded extends HttpServlet {

/**

* Processes requests for both HTTPGETandPOSTmethods.

* @param request servlet request

* @param response servlet response

*/

// 定义文件的上传路径

private StringuploadPath="d:\\a\\";

// 限制文件的上传大小

private intmaxPostSize=100* 1024 * 1024;

public FileUploaded() {

super();

}

public void destroy() {

super.destroy();

}

protected void processRequest(HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

System.out.println("Access !");

response.setContentType("text/html;charset=UTF-8");

PrintWriterout=response.getWriter();

//保存文件到服务器中

DiskFileItemFactoryfactory=newDiskFileItemFactory();

factory.setSizeThreshold(4096);

ServletFileUploadupload=newServletFileUpload(factory);

upload.setSizeMax(maxPostSize);

try {

ListfileItems=upload.parseRequest(request);

Iteratoriter=fileItems.iterator();

while (iter.hasNext()) {

FileItemitem= (FileItem) iter.next();

if (!item.isFormField()) {

Stringname=item.getName();

System.out.println(name);

try {

item.write(new File(uploadPath + name));

// SaveFiles=newSaveFile();

// s.saveFile(name);

} catch (Exception e) {

e.printStackTrace();

}

}

}

} catch (FileUploadException e) {

e.printStackTrace();

System.out.println(e.getMessage() + "结束");

}

}

//

/**

* Handles the HTTPGETmethod.

* @param request servlet request

* @param response servlet response

*/

protected void doGet(HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

processRequest(request, response);

}

/**

* Handles the HTTPPOSTmethod.

* @param request servlet request

* @param response servlet response

*/

protected void doPost(HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

processRequest(request, response);

}

/**

* Returns a short description of the servlet.

*/

public String getServletInfo() {

return "Short description";

}

//

}

如果使得你的Servlet被访问，你还需要在WEB-INF/web.xml 添加如下的xml语句：[在中]

FileUploaded

upload.FileUploaded

FileUploaded

/FileUploaded

效果图：