Flex upload and download with Blazeds

With Actionscript 3 and Flashplayer 10 you can now use the new FileReference features. For example you download and upload a file with RemoteObjects ( Blazeds / LifeCycle ). In the early days you had to use a upload and download servlets.
To use the new FileReference features please read these two articles flexexamples.com and using flashplayer 10

Here are some screenshots of the flex application.
First we can upload a file. The datagrid show the status of the uploaded files.

Off course we can download some files from a remote server. First we need to get a list of the remote files. For this we need to press the Get remote files button.

We can select a file and press the Retrieve File Button. When the status is ready we can save this file by pressing the Save File Button.

Here you can download the Flex source code

The code of the upload panel

<?xml version="1.0" encoding="utf-8"?>
<mx:Panel xmlns:mx="http://www.adobe.com/2006/mxml"
layout="vertical" width="100%"  height="100%"
title="Upload Files">


<mx:Script>
 <![CDATA[
  import mx.rpc.AsyncToken;
  import mx.rpc.events.FaultEvent;
  import mx.rpc.events.ResultEvent;
  
  private var refUploadFile:FileReference;

  private var UploadFiles:Array = new Array();
 
 
  // Called to add file(s) for upload
  private function addFiles():void {
   refUploadFile = new  FileReference();
     refUploadFile.browse();
     refUploadFile.addEventListener(Event.SELECT,onFileSelect);
     refUploadFile.addEventListener(Event.COMPLETE,onFileComplete);
  }

  // Called when a file is selected
  private function onFileSelect(event:Event):void {
   UploadFiles.push({  name:refUploadFile.name,
        size:formatFileSize(refUploadFile.size),
        status:"initial"});
   listFiles.dataProvider  = UploadFiles;
   listFiles.selectedIndex = UploadFiles.length - 1;
   
               refUploadFile.load();
               for ( var i:int = 0 ; i <  UploadFiles.length ; i++ ) {
                 if( UploadFiles[i].name == refUploadFile ) {
                  UploadFiles[i].status = "loaded";
       listFiles.dataProvider  = UploadFiles;
                  break;
                 }
               }
  }

  // Called to format number to file size
  private function formatFileSize(numSize:Number):String {
   var strReturn:String;
   numSize = Number(numSize / 1000);
   strReturn = String(numSize.toFixed(1) + " KB");
   if (numSize > 1000) {
    numSize = numSize / 1000;
    strReturn = String(numSize.toFixed(1) + " MB");
    if (numSize > 1000) {
     numSize = numSize / 1000;
     strReturn = String(numSize.toFixed(1) + " GB");
    }
   }   
   return strReturn;
  }

    private function onFileComplete(event:Event):void
    {
      refUploadFile = event.currentTarget as FileReference;
      var data:ByteArray = new ByteArray();
      refUploadFile.data.readBytes(data,0,refUploadFile.data.length);
              
      var token:AsyncToken = AsyncToken(
                                remoteUpload.doUpload(data, refUploadFile.name)
                                );
     
            token.kind = refUploadFile.name;
                        
               for ( var i:int = 0 ; i <  UploadFiles.length ; i++ ) {
                 if( UploadFiles[i].name == refUploadFile ) {
                  UploadFiles[i].status = "upload";
       listFiles.dataProvider  = UploadFiles;
                  break;
                 }
               }
    }

    private function uploadResultHandler(event:ResultEvent):void
    {
               for ( var i:int = 0 ; i <  UploadFiles.length ; i++ ) {
                 if( UploadFiles[i].name == event.token.kind ) {
                  UploadFiles[i].status = "finished";
       listFiles.dataProvider  = UploadFiles;
                  break;
                 }
               }
    }

    private function faultResultHandler(event:FaultEvent):void
    {
               for ( var i:int = 0 ; i <  UploadFiles.length ; i++ ) {
                 if( UploadFiles[i].name == event.token.kind ) {
                  UploadFiles[i].status = "error";
       listFiles.dataProvider  = UploadFiles;
                  break;
                 }
               }
    }

 
 ]]>
</mx:Script>

<mx:RemoteObject id="remoteUpload" destination="FileUtils"
 result="uploadResultHandler(event)"
 fault="faultResultHandler(event)"/>


<mx:Canvas width="100%" height="100%">
 <mx:DataGrid id="listFiles" left="0" top="0" bottom="0" right="0"
  allowMultipleSelection="true" verticalScrollPolicy="on"
  draggableColumns="false" resizableColumns="false" sortableColumns="false">
  <mx:columns>
   <mx:DataGridColumn headerText="File" width="150" dataField="name" wordWrap="true"/>
   <mx:DataGridColumn headerText="Size" width="50" dataField="size" textAlign="right"/>
   <mx:DataGridColumn headerText="Status" width="50" dataField="status" textAlign="right"/>
  </mx:columns>
 </mx:DataGrid>
</mx:Canvas>
<mx:ControlBar horizontalAlign="center" verticalAlign="middle">
 <mx:Button id="btnAdd" toolTip="Add file(s)" click="addFiles()"
  label="Upload Files" width="150"/>
</mx:ControlBar>
</mx:Panel>

The code of the download panel

<?xml version="1.0" encoding="utf-8"?>
<mx:Panel xmlns:mx="http://www.adobe.com/2006/mxml" layout="vertical"
width="100%" height="100%" title="Download Files">

<mx:Script>
 <![CDATA[
  import mx.collections.ArrayCollection;
  import mx.rpc.events.FaultEvent;
  import mx.rpc.events.ResultEvent;
  import mx.rpc.AsyncToken;

  private var UploadFiles:Array = new Array();
  private var UploadFilesColl:ArrayCollection = new ArrayCollection();
  private var fileData:ByteArray = new ByteArray();
  private var fileName:String;

 
    private function uploadResultHandler(event:ResultEvent):void
    {
      if ( event.token.kind == "remoteFileList") {
              UploadFilesColl = event.result as ArrayCollection;
              for ( var i:int = 0 ; i <  UploadFilesColl.length ; i++ ) {
                UploadFiles.push({  name:UploadFilesColl[i]
                                 ,  status:"initial"});
              }
              listFiles.dataProvider = UploadFiles;
             } else  {
                fileData = event.result as ByteArray;
                fileName = event.token.kind;
                for ( var b:int = 0 ; b <  UploadFiles.length ; b++ ) {
                 if( UploadFiles[b].name == event.token.kind ) {
                  UploadFiles[b].status = "Ready";
       listFiles.dataProvider  = UploadFiles;
                  break;
                 }
               }

             }
    }

    private function faultResultHandler(event:FaultEvent):void
    {
    }

    private function saveFile(event:Event):void
    {
      var fileReference:FileReference = new FileReference();
      fileReference.save(fileData,fileName);
    }

    private function getRemoteFiles(event:Event):void
    {
      var token:AsyncToken = AsyncToken(remoteDownload.getDownloadList());
            token.kind = "remoteFileList";
    }

    private function getDownload(event:Event):void
    {
      var token:AsyncToken = AsyncToken(
          remoteDownload.doDownload(listFiles.selectedItem.name));
            token.kind = listFiles.selectedItem.name;
    }
 ]]>
</mx:Script>


<mx:RemoteObject id="remoteDownload" destination="FileUtils"
 result="uploadResultHandler(event)"
 fault="faultResultHandler(event)"/>


<mx:Canvas width="100%" height="100%">
 <mx:DataGrid id="listFiles" left="0" top="0" bottom="0" right="0"
  verticalScrollPolicy="on"
  draggableColumns="false" resizableColumns="false" sortableColumns="false">
  <mx:columns>
   <mx:DataGridColumn headerText="File" width="150" dataField="name" wordWrap="true"/>
   <mx:DataGridColumn headerText="Status" width="50" dataField="status" textAlign="right"/>
  </mx:columns>

 </mx:DataGrid>
</mx:Canvas>
<mx:ControlBar horizontalAlign="center" verticalAlign="middle">
 <mx:Button id="btnList" toolTip="List remote files"
  width="150"
  label="Get Remote Files"
  click="getRemoteFiles(event)"/>
 <mx:Button id="btnRetrieve" toolTip="Retrieve file"
   width="150" click="getDownload(event)" label="Retrieve File"/>
 <mx:Button id="btnSave" toolTip="Save file"
   width="150" click="saveFile(event)" label="Save File"/>
</mx:ControlBar>



</mx:Panel>

The java code

package nl.ordina.flex;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;

import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;

import java.util.ArrayList;
import java.util.List;

public class FileUtils {


   public String  doUpload(byte[] bytes, String fileName) throws Exception
   {
       fileName = System.getProperty("java.io.tmpdir") + "/" + fileName;
       File f = new File(fileName);
       FileOutputStream fos = new FileOutputStream(f);
       fos.write(bytes);
       fos.close();
       return "success";
   }

   public List  getDownloadList()
   {
       File dir = new File(System.getProperty('java.io.tmpdir'));
       String[] children = dir.list();
       List dirList = new ArrayList();
       if (children == null) {
              // Either dir does not exist or is not a directory
          } else {
              for (int i=0; i<children.length; i++) {
                  // Get filename of file or directory
                  dirList.add( children[i]);
              }
          }
       return dirList;
   }

   public byte[] doDownload(String fileName)
   {
       FileInputStream fis;
       byte[] data =null;
       FileChannel fc;

       try {
           fis = new FileInputStream(System.getProperty("java.io.tmpdir") + "/" + fileName);
           fc = fis.getChannel();
           data = new byte[(int)(fc.size())];
           ByteBuffer bb = ByteBuffer.wrap(data);
           fc.read(bb);
       } catch (FileNotFoundException e) {
           // TODO
       } catch (IOException e) {
           // TODO
       }
       return data;
   }
}