Socket三次握手例子：

package
 {
     import flash.display.Sprite;
     import flash.events.ProgressEvent;
     import flash.net.Socket;
     import flash.utils.ByteArray;
     /**
      *
      * 三次握手连接socket
      * 来源socket编程
      */
     public class SocketHandshake extends Sprite
     {
         public const DETERMINE_VERSION:int = 0;
         public const RECEIVE_CHALLENGE:int = 1;
         public const NORMAL:int = 2;
         private var stateMap:Object;
         private var currentState:int;
         private var socket:Socket;
         public function SocketHandshake( )
         {
             stateMap = new Object( );
             stateMap[DETERMINE_VERSION] = readVersion;
             stateMap[RECEIVE_CHALLENGE] = readChallenge;
             stateMap[NORMAL] = readNormalProtocol;
             currentState = DETERMINE_VERSION;
             socket = new Socket( );
             socket.addEventListener( ProgressEvent.SOCKET_DATA， onSocketData );
             socket.connect( "localhost"， 9000 );
             trace(currentState);
         }
         private function onSocketData( event:ProgressEvent ):void
         {
             trace(currentState);
             var processFunc:Function = stateMap[currentState];
             processFunc( );
         }
         private function readVersion( ):void
         {
 
             try
             {
                 var version:int = socket.readInt();
                 trace(version);
             }
             catch (error:Error)
             {
                 trace("error:"+error);
             }
             currentState = RECEIVE_CHALLENGE;
             socket.writeInt( version );
             socket.flush( );
         }
         private function readChallenge( ):void
         {
             var bytes:ByteArray = new ByteArray( );
             socket.readBytes( bytes， 0， 8 );
             currentState = NORMAL;
             socket.writeBytes( bytes );
             socket.flush( );
         }
         private function readNormalProtocol( ):void
         {
         }
     }
 }