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/