flex文件上传

本文讲的是通过Blazeds实现Flex文件上传，关于Blazeds的配置在这里就不赘述了，下面直接开讲。　　 
　说到Flex上传文件，就不得不用到FileReference了，下图是FileReference的属性： 
　可见data属性是ByteArray格式的，由其可以想到如果我们要上传文件，必然是将文件已比特流的形式通过网络上传到服务器。既然如此，我们就在服务器端写一个接受数据的JAVA类UploadFile。 
UploadFile.java 
1 package upload; 
2 
3 import java.io.File; 
4 import java.io.FileOutputStream; 
5 
6 public class UploadFile { 
7 public void uploadFile(byte[] content, String fileName) 
8 throws Exception{ 
9 File file = new File("路径"+fileName); //路径是你存文件的路径 比如c:\upload\
10 FileOutputStream stream = new FileOutputStream(file); 
11 if(content != null) 
12 stream.write(content); 
13 stream.close(); 
14 } 
15 } 
　　我在做的时候新建文件路径使用的是相对路径，在部署到blazeds之后发现文件总是上传不成功，改成绝对路径之后问题解决。其次，我用的 Flex IDE是Flash Builder4(从4代开始不再叫Flex Builder)，经常莫名其妙地出现上传文件的data属性为null的情况，因此加了一个判断content是否为null的语句，各位可以忽略。 
　　做完服务器的接收部分了，现在可以开始写我们的上传代码了。 

PopUpImage.mxml 
<?xml version="1.0" encoding="utf-8"?>
<s:Application xmlns:fx="http://ns.adobe.com/mxml/2009"
      xmlns:s="library://ns.adobe.com/flex/spark"
      xmlns:mx="library://ns.adobe.com/flex/mx" minWidth="955" minHeight="600"
      currentState="pre_upload"
      creationComplete="init()">
 <s:layout>
  <s:BasicLayout/>
 </s:layout>
 <fx:Script>
  <![CDATA[
   //import mx.events.ImageUploadedEvent;
   import flash.events.Event;
   import flash.net.FileFilter;
   import flash.net.FileReference;
   import mx.controls.Alert;
   import mx.managers.PopUpManager;
   import mx.rpc.events.FaultEvent;
   import mx.rpc.events.ResultEvent;
   import mx.rpc.remoting.mxml.RemoteObject;
   
   private var fileRef:FileReference = new FileReference();
   
   private var upload:RemoteObject = new RemoteObject();
   private function init():void{
    upload.destination="UploadFile";
   }
   
   private function pickFile(evt:MouseEvent):void
   {
    var imageTypes:FileFilter = new FileFilter("图片 (*.jpg, *.jpeg, *.gif,*.png)", "*.jpg; *.jpeg; *.gif; *.png");
    var allTypes:Array = new Array(imageTypes);
    fileRef.addEventListener(Event.SELECT, selectHandler);
    fileRef.addEventListener(ProgressEvent.PROGRESS, progressHandler);
    fileRef.addEventListener(Event.COMPLETE, completeHandler);
    try{
     fileRef.browse(allTypes);
    }catch (error:Error){
     trace("Unable to browse for files."+error.toString());
    }
   }
   
   private function progressHandler(evt:ProgressEvent):void
   {
    lb_progress.text = " 已上传 " + (evt.bytesLoaded/1024).toFixed(2)+ " K，共 " + (evt.bytesTotal/1024).toFixed(2) + " K";
    var proc: uint = evt.bytesLoaded / evt.bytesTotal * 100;
    progress.setProgress(proc, 100);
    progress.label= "当前进度: " + " " + proc + "%";
   }
   
   private function selectHandler(evt:Event):void
   {
    currentState = "uploading";
    fileRef.load();
   }
   
   private function completeHandler(evt:Event):void{
    currentState = "post_upload";
    upload.uploadFile(fileRef.data,fileRef.name);
    image_post_upload.source = fileRef.data;
   }
   
  ]]>
 </fx:Script>
 <s:states>
  <s:State name = "pre_upload"/>
  <s:State name = "uploading"/>
  <s:State name = "post_upload"/>
 </s:states>
 <s:Button includeIn="pre_upload" label="从电脑上上传图片" width="119" click="pickFile(event)" horizontalCenter="-1" y="29"/>
 <mx:ProgressBar id="progress" includeIn="uploading" x="43" y="43" width="153"/>
 <s:Label id="lb_progress" includeIn="uploading" x="45" y="10" width="149" height="25"/>
 <s:Label id="lb_post_upload" includeIn="post_upload" x="108" y="21" width="124" height="32" fontSize="16" text="upload success!" fontFamily="Arial" color="#3374DE"/>
 <mx:Image id="image_post_upload" includeIn="post_upload" x="10" y="10" width="67" height="67"/>
</s:Application>
　   组件有三个状态，分别为upload前、中、后期。 
　　这里重点说的是RemoteObject，需要在remoting-config.xml文件中进行配置。 

remoting-config.xml的位置是在Web-inf\flex里  另外编译的时候要加上参数指向这个文件 参考我的文章

http://hi.baidu.com/caidows/blog/item/19366bc61e79f9089c163de7.html

remoting-config.xml添加
1 <destination id="uploadFile" channels="my-amf"> 
2 <properties> 
3 <source>upload.UploadFile</source> 
4 </properties> 
5 </destination> 
以上就是一个完整的Flex通过Blazeds上传文件的过程。

原作者：mikel 转自：http://www.douban.com/group/topic/15982509/