Flex+Java Servlet文件上传实例

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[url]http://commons.apache.org[/url] 下载common-fileupload-1.1.1.jar以及common-io-1.2.jar两个包。
前台Flex代码：

<?xml version="1.0" encoding="utf-8"?>  
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute" xmlns="*" creationComplete="init();">  
<mx:Script>  
<![CDATA[  
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");  
}  

}  
}  
]]>  
</mx:Script>  

<mx:Canvas width="100%" height="100%" x="10" y="170" fontSize="15">  
<mx:VBox width="100%" horizontalAlign="center">  
<mx:Label id="lbProgress" text="上传"/>  
<mx:ProgressBar id="bar" labelPlacement="bottom" themeColor="#F20D7A"  
minimum="0" visible="true" maximum="100" label="当前进度: 0%"  
direction="right" mode="manual" width="200"/>  

<mx:Button label="上传文件" click="upload();"/>  
</mx:VBox>  
</mx:Canvas>  
</mx:Application>  

http://localhost:8080/FileUploaded/FileUploaded
就是你自己写的servlet的路径了。
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 HTTP <code>GET</code> and <code>POST</code> methods.   
     * @param request servlet request   
     * @param response servlet response   
     */   
    // 定义文件的上传路径   

    private String uploadPath = "d:\\a\\";   

// 限制文件的上传大小   

    private int maxPostSize = 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");   
        PrintWriter out = response.getWriter();   

//保存文件到服务器中   

        DiskFileItemFactory factory = new DiskFileItemFactory();   
        factory.setSizeThreshold(4096);   
        ServletFileUpload upload = new ServletFileUpload(factory);   
        upload.setSizeMax(maxPostSize);   
        try {   
            List fileItems = upload.parseRequest(request);   
            Iterator iter = fileItems.iterator();   
            while (iter.hasNext()) {   
                FileItem item = (FileItem) iter.next();   
                if (!item.isFormField()) {   
                    String name = item.getName();   
                    System.out.println(name);   
                    try {   
                        item.write(new File(uploadPath + name));   
                       // SaveFile s = new SaveFile();   

                       // s.saveFile(name);   

                    } catch (Exception e) {   
                        e.printStackTrace();   
                    }   
                }   
            }   
        } catch (FileUploadException e) {   
            e.printStackTrace();   
            System.out.println(e.getMessage() + "结束");   
        }   
    }   

    // <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code.">  

    /**   
     * Handles the HTTP <code>GET</code> method.   
     * @param request servlet request   
     * @param response servlet response   
     */   
    protected void doGet(HttpServletRequest request, HttpServletResponse response)   
            throws ServletException, IOException {   
        processRequest(request, response);   
    }   

    /**   
     * Handles the HTTP <code>POST</code> method.   
     * @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";   
    }   
    // </editor-fold>  

}

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<web-app>中]

<!-- For file uploaded -->  
   <servlet>  
        <servlet-name>FileUploaded</servlet-name>  
        <servlet-class>upload.FileUploaded</servlet-class>  
    </servlet>  

    <servlet-mapping>  
        <servlet-name>FileUploaded</servlet-name>  
        <url-pattern>/FileUploaded</url-pattern>  
    </servlet-mapping>  

参考：

[url]http://blog.youkuaiyun.com/meteorlWJ/archive/2008/06/01/2450234.aspx [/url]

[url]http://swingchen.bokee.com/5943371.html [/url]

[url]http://www.cnblogs.com/dannyr/archive/2006/11/13/559006.html [/url]

源码下载
[url]http://yexin218.iteye.com/topics/download/1efef75f-a23f-3f95-8533-4478de478b72[/url]