import javax.swing.JTextArea;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
 
import java.net.ServerSocket;
import java.net.Socket;
 
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
import java.util.concurrent.locks.Condition;
 
import java.io.IOException;
 
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
 
import javax.swing.SwingUtilities;
 
 
public class MorseServer extends JFrame
{
	private JTextArea serverDisplay;
	private ServerSocket server; // server socket to connect with users
	private ExecutorService messageExchange;
	private Lock messageLock;
	private Condition userTwoConnect;
	private Client[] client;
	private boolean twoUserConnected = false;
	private static String messageBuffer;
 
	public MorseServer()
	{
		super("Morse Code Server");
 
		serverDisplay = new JTextArea( "Waiting for connection\n" );
		serverDisplay.setEditable( false );
		add( new JScrollPane( serverDisplay ) );
 
		messageExchange = Executors.newFixedThreadPool(2);
		messageLock = new ReentrantLock();
 
		userTwoConnect = messageLock.newCondition();
 
		client = new Client[ 2 ];
	}
 
	public void execute()
	{
		try
		{
			server = new ServerSocket( 22222, 2 );
		}
		catch( IOException ioException )
		{
			ioException.printStackTrace();
			System.exit(1);
		}
 
		waitForConnection();
 
		messageExchange.execute( client[0] );
		messageExchange.execute( client[1] );
 
		messageLock.lock();
 
		try
		{
			client[ 0 ].setSuspended(false);
			userTwoConnect.signal();
		}
		finally
		{
			messageLock.unlock();
		}
	}
 
	public void waitForConnection()
	{
		messageBuffer = new String();
 
		for( int i = 0; i < client.length; i++ )
		{
			try
			{
				client[ i ] = new Client( server.accept(), i, messageBuffer ); // waits for connection
				messageExchange.execute( client[ i ] );
			}
			catch( IOException ioException )
			{
				ioException.printStackTrace();
				System.exit(1);
			} // end catch
		}// end for
 
		twoUserConnected = true;
	}
 
	private void displayInformation( final String info )
	{
		SwingUtilities.invokeLater(
				new Runnable()
				{
					public void run()
					{
						serverDisplay.append( "\n" + info );
					}
				}
		);
	}
 
	private class Client implements Runnable
	{
		private Socket connection;
		private int userNumber;
		private ObjectInputStream input;
		private ObjectOutputStream output;
		private boolean suspended = true;
		private String message;
		//private Condition canRead;
		//private Condition canWrite;
 
		public Client( Socket socket, int number, String msg )
		{
			connection = socket;
			userNumber = number;
			messageBuffer = msg;
			//canRead = messageLock.newCondition();
			//canWrite = messageLock.newCondition();
 
 
			try
			{
				input = new ObjectInputStream( connection.getInputStream() );
				output = new ObjectOutputStream( connection.getOutputStream() );
			}
			catch( IOException ioException )
			{
				ioException.printStackTrace();
				System.exit(1);
			}
		}
 
 
		public void run()
		{
			try
			{		
				displayInformation( "User Number: " + userNumber + " connected\n" );
				output.writeObject( "Connection sucessful!\n" );
				output.flush();
 
				if( !twoUserConnected )
				{
					if( userNumber == 0 )
					{
						output.writeObject( "Waiting for correspondent\n" );
						output.flush();
 
						messageLock.lock(); // wating for second client
 
						try
						{
							while( suspended )
							{
								userTwoConnect.await();
							}
						}
						catch( InterruptedException exception )
						{
							exception.printStackTrace();
						}
						finally
						{
							messageLock.unlock();
						}
 
						output.writeObject( "Second user connected!\n");
						output.flush();
					}
					else
					{
						output.writeObject( "Connection sucessful!\n" );
						output.flush();
					}
				}
 
				String msg;
 
				while( true )
				{
 
					if ( input.equals(null) )
					{
						continue;
					}
					else
					{ 
						messageBuffer = ( String ) input.readObject();
						msg = messageBuffer;
						displayInformation( messageBuffer );
 
				//while ( !userTerminate( message ) )
				//{
					//messageLock.lock();
 
 
 
						output.writeObject ( messageBuffer );
						output.flush();
						Thread.sleep(10000);
 
					}
				}
			}
			catch( ClassNotFoundException exception )
			{
				exception.printStackTrace();
			}
			catch( IOException ioException )
			{
				ioException.printStackTrace();
			}
		catch( InterruptedException exception )
		{
			exception.printStackTrace();
		}
			finally
			{
				try
				{
					messageLock.unlock();
					connection.close();
				}
				catch( IOException ioException )
				{
					ioException.printStackTrace();
					System.exit(1);
				}// end catch
			} // end finally
		} // end method run
 
		private boolean userTerminate( String msg ) 
		{
			if ( msg.equals( "User>>> TERMINATE" ) )
				return true;
			else
				return false;
		}
 
		public void setSuspended( boolean state )
		{
			suspended = state;
		}
	}
}

import javax.swing.JFrame;
 
public class MorseServerTest 
{
	public static void main( String args[] )
	{
		MorseServer application = new MorseServer();
		application.setSize(300,300);
		application.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
		application.setResizable(false);
		application.setVisible(true);
		application.execute();
	}
}