Flex、java实现文件上传

FileUpload.java:

 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;
 @SuppressWarnings("serial")
 public class FileUpload extends HttpServlet
 {
     //定义文件上传的路径
     private String uploadPath = "d://a//";

     private int maxPostSize = 100*1024*1024;
     public FileUpload()
     {
         super();
     }
     public void destroy()
     {
         super.destroy();
     }

     @SuppressWarnings("unchecked")
     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();
         out.print("已连接上!");

         //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));
                     }
                     catch(Exception e)
                     {
                         e.printStackTrace();
                     }
                 }
             }
         }
         catch(FileUploadException e)
         {
             e.printStackTrace();
             System.out.println(e.getMessage()+"结束");
         }
     }
     public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
     {
         processRequest(request, response);
     }
     public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
     {
         processRequest(request, response);
     }
 }

 

FileUpload.mxml

 <?xml version="1.0" encoding="utf-8"?>
 <mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute" 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/FileUpload/servlet/FileUpload");
                     try
                     {
                         file.upload(request);
                     }
                     catch(error:Error)
                     {
                         Alert.show("上传失败");
                     }
                 }
             }
         ]]>
     </mx:Script>
     <mx:Canvas width="100%" height="100%" x="10" y="170" fontSize="12">
         <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>

 

配置到tomcat上的时候，要在web-inf/lib里面要加入连个包：

1. commons-fileupload-1.2.1.jar
2. commons-io-1.4.jar

这两个包在网上很容易下载到。加入包以后要修改web.xml，在跟下加入下面servlet声明：

 <servlet>
     <servlet-name>FileUpload</servlet-name>
     <servlet-class>FileUpload</servlet-class>
 </servlet>
 <servlet-mapping>
     <servlet-name>FileUpload</servlet-name>
     <url-pattern>/servlet/FileUpload</url-pattern>
 </servlet-mapping>

我的文件是上传到D盘的a文件夹，要确保该目录存在。上传个图片试试吧！