This AIR application demonstrates how to download, pause and resume downloads of larger files(mp3, flv, etc) and save to the user’s computer. Big Thanks to Benjamin Dobler for his blog post Resumable Downloads with AIR.

Sample Files:
ResumableDownloader.air (AIR, 524 KB)

NOTE: You will need AIR 2 BETA – Download the Runtime

Files: ServerSocketDemo.air, SocketDemo.air, SocketDemo2.air
Source Codes: ServerSocketDemo.mxml, SocketDemo.mxml

ContactMessage.as

package com.mariusht.contactmanager.common.messages
{
    import com.mariusht.contactmanager.common.model.vo.ContactVO;

    import org.puremvc.as3.multicore.utilities.pipes.messages.Message;

    public class ContactMessage extends Message
    {
        protected static const NAME:String = 'ContactMessage';

        public static const ADD_CONTACT:String = NAME + '/message/contact/add';
        public static const CONTACT_ADDED:String = NAME + '/message/contact/added';
        public static const CONTACT_ADD_FAILED:String = NAME + '/message/contact/add/failed';

        public static const UPDATE_CONTACT:String = NAME + '/message/contact/update';
        public static const CONTACT_UPDATED:String = NAME + '/message/contact/updated';
        public static const CONTACT_UPDATE_FAILED:String = NAME + '/message/contact/update/failed';

        public static const REMOVE_CONTACT:String = NAME + '/message/contact/remove';
        public static const CONTACT_REMOVED:String = NAME + '/message/contact/removed';
        public static const CONTACT_REMOVE_FAILED:String = NAME + '/message/contact/remove/failed';

        public function ContactMessage(type:String, contact:ContactVO=nulll)
        {
            // add headers if needed
            super(type, null, contact);
        } 

        public function get contact():ContactVO
        {
            return body as ContactVO;
        }
    }
}

JunctionMediator.as

...
override public function handlePipeMessage(message:IPipeMessage):void
{
    switch(message.getType())
    {
        case ScreenMessage.GET:
            //
            break;
        case ContactMessage.CONTACT_ADDED:
            contactsProxy.addContact( ContactMessage(message).contact );
            break;
        case ContactMessage.CONTACT_UPDATED:
            contactsProxy.updateContact( ContactMessage(message).contact );
            break;
        case ContactMessage.CONTACT_REMOVED:
            contactsProxy.removeContact( ContactMessage(message).contact );
            break;
        case ItemMessage.ITEM_ADDED:
            itemsProxy.addItem( ItemMessage(message).item );
            break;
        case ItemMessage.ITEM_UPDATED:
            itemsProxy.updateItem( ItemMessage(message).item );
            break;
        case ItemMessage.ITEM_REMOVED:
            itemsProxy.removeItem( ItemMessage(message).item );
            break;
    }
}
...

import mx.events.FlexEvent;

// Flex 4
private function creationComplete(event:FlexEvent):void
{
    textInput.selectRange(textInput.text.length, textInput.text.length);
    textInput.setFocus();
}

// load the update-descriptor
var loader:URLLoader = new URLLoader;
loader.addEventListener(Event.COMPLETE, onLoadComplete);
loader.load(new URLRequest('http://mariusht.com/files/products/notelist/update.xml'));

2. Check and see if a user has the latest version of an AIR app installed.

private function onLoadComplete(event:Event):void
{
    // ignore xml declaration
    var str:String = URLLoader(event.target).data as String;
    var index:int = str.indexOf('<update');
    str = str.substr(index, str.length);

    // convert String to XML
    var remoteAppXML:XML = XML(str);
    var ns:Namespace = remoteAppXML.namespace();

    // get new version number
    var version:String = remoteAppXML.ns::version;

    // get current version number
    var appXML:XML = NativeApplication.nativeApplication.applicationDescriptor;
    var ns:Namespace = appXML.namespace();
    currentVersion = appXML.ns::version;

    if(currentVersion != version)
    {
        // download AIR file
    }
}

3. Download and save the AIR file. Don’t forget to call Updater.update() function.

public class UpdateAppCommand extends SimpleCommand implements ICommand
{
    override public function execute(note:INotification):void
    {
        // download updated .air file
        urlStream = new URLStream();
        fileData = new ByteArray();
        urlStream.addEventListener(Event.COMPLETE, loaded);
        urlStream.load(
            new URLRequest('http://mariusht.com/files/products/notelist/NoteList.air'));
    } 

    private function loaded(event:Event):void
    {
        urlStream.readBytes(fileData, 0, urlStream.bytesAvailable);
        writeAirFile();
    } 

    private function writeAirFile():void
    {
        var file:File = File.applicationStorageDirectory.resolvePath('NoteList.air');
        var fileStream:FileStream = new FileStream;
        fileStream.open(file, FileMode.WRITE);
        fileStream.writeBytes(fileData, 0, fileData.length);
        fileStream.close();

        var versionProxy:VersionProxy =
            facade.retrieveProxy(VersionProxy.NAME) as VersionProxy;
        var updater:Updater = new Updater;
        updater.update(file, versionProxy.version);
    } 

    private var urlStream:URLStream;
    private var fileData:ByteArray;

Related Links:
Updating AIR applications (Adobe AIR 1.5 LiveDocs)

I will be happy to tell you that i have been using this application quite often.

You can install application from here: NoteList

<?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/halo"
               viewSourceURL="srcview/index.html"> 

    <fx:Script>
        <![CDATA[
            import com.adobe.serialization.json.JSON;

            import mx.rpc.events.ResultEvent;
            import mx.rpc.http.HTTPService;

            private function getCd():void
            {
                var httpService:HTTPService = new HTTPService();
                httpService.url = 'assets/cd.php?getCd';
                httpService.useProxy = false;
                httpService.method = URLRequestMethod.POST;
                httpService.resultFormat = HTTPService.RESULT_FORMAT_TEXT;
                httpService.addEventListener(ResultEvent.RESULT, jsonResultHandler);
                httpService.send();
            } 

            private function jsonResultHandler(event:ResultEvent):void
            {
                var rawData:String = String(event.result);
                var cd:Object = JSON.decode(rawData);
                titleInput.text = cd.title;
                artistInput.text = cd.artist;
                countryInput.text = cd.country;
                companyInput.text = cd.company;
                priceInput.text = cd.price;
                yearInput.text = cd.year;
            }
        ]]>
    </fx:Script> 

    <fx:Declarations>
        <!-- Place non-visual elements (e.g., services, value objects) here -->
    </fx:Declarations>
    <mx:Form x="19" y="22">
        <mx:FormItem label="title">
            <s:TextInput id="titleInput"/>
        </mx:FormItem>
        <mx:FormItem label="artist">
            <s:TextInput id="artistInput"/>
        </mx:FormItem>
        <mx:FormItem label="country">
            <s:TextInput id="countryInput"/>
        </mx:FormItem>
        <mx:FormItem label="company">
            <s:TextInput id="companyInput"/>
        </mx:FormItem>
        <mx:FormItem label="price">
            <s:TextInput id="priceInput"/>
        </mx:FormItem>
        <mx:FormItem label="year">
            <s:TextInput id="yearInput"/>
        </mx:FormItem>
    </mx:Form>
    <s:Button x="19" y="224" label="Get JSON Object" click="getCd()"/>
</s:Application>

PHP script:

<?php

    class Cd
    {
        public $title;
        public $artist;
        public $country;
        public $company;
        public $price;
        public $year;
    }
    
    if(isset($_GET['getCd']))
    {
        $cd = new Cd();
        $cd->title = 'Big Willie style';
        $cd->artist = 'Will Smith';
        $cd->country = 'USA';
        $cd->company = 'Columbia';
        $cd->price = '$9.90';
        $cd->year = '1997';
        echo json_encode($cd);
    }
?>