server.java

collection of java programs having gui applications

import java.io.*;
import java.net.*;
import java.util.Vector;
import java.util.Enumeration;
public class server
{
		private int port=5001;
	private boolean li=true;
	private Vector clients=new Vector();
	public static void main(String a[])
	{
		System.out.println(" Press ctrl-c to Quit.");
		new server().server();
	}
	 void server()
	{
		ServerSocket serverSock=null;
		try
		{
			InetAddress serverAddr=InetAddress.getByName(null);
			System.out.println("Waiting for"+serverAddr.getHostName()+"on  port"+port);
			serverSock=new ServerSocket(port,50);
		}
		catch(IOException e)
		{
			System.out.println(e.getMessage()+":Failed");
			return;
		}
		while(li)
		{
			try
			{
				Socket socket=serverSock.accept();
				System.out.println("Accept   "+socket.getInetAddress().getHostName());
				DataOutputStream remoteOut= new  DataOutputStream(socket.getOutputStream());
				clients.addElement(remoteOut);
				new ServerHelper(socket,remoteOut,this).start();
			}
			catch(IOException e)
			{
				System.out.println(e.getMessage()+":Failed");
			}
		}
		if(serverSock !=null)
		{
			try
			{
				serverSock.close();
			}
			catch(IOException x)
			{
			}
		}
	}
	synchronized Vector getClients()
	{
		return clients;
	}
	synchronized void removeFromClients(DataOutputStream remoteOut)
	{
		clients.removeElement(remoteOut);
	}
}
class ServerHelper extends Thread
{
	private Socket sock;
	private DataOutputStream remoteOut;
	private server server;
	private boolean li=true;
	private DataInputStream remoteIn;
	ServerHelper(Socket sock,DataOutputStream remoteOut,server
server) throws IOException
	{
		this.sock=sock;
		this.remoteOut=remoteOut;
		this.server=server;
		remoteIn=new DataInputStream(sock.getInputStream());
	}
	public synchronized void run()
	{
		String s;
		try
		{
			while(li)
			{
				s=remoteIn.readUTF();
				broadcast(s);
			}
		}
		catch(IOException e)
		{
			System.out.println(e.getMessage()+"connection lost");
		}
		finally
		{
			try
			{
				cleanUp();
			}
			catch (IOException x)
			{
			}
		}
	}
	private void broadcast(String s)
	{
		Vector clients=server.getClients();
		DataOutputStream dataOut=null;
		for(Enumeration e=clients.elements();
		e.hasMoreElements(); )
		{
		dataOut=(DataOutputStream)(e.nextElement());
		if(!dataOut.equals(remoteOut))
		{
		try
		{
		dataOut.writeUTF(s);
		}
		catch(IOException x)
		{
		System.out.println(x.getMessage()+"Failed");
		server.removeFromClients(dataOut);
	}

}
}
}

private void cleanUp() throws IOException
{
	if(remoteOut!=null)
	{
		server.removeFromClients(remoteOut);
		remoteOut.close();
		remoteOut=null;
	}

	if(remoteIn!=null)
	{
		remoteIn.close();
		remoteIn=null;
	}

	if(sock!=null)
	{
		sock.close();
		sock=null;
	}
}
protected void finalize() throws Throwable
{
	try
	{
		cleanUp();
	}
	catch(IOException x)
	{
	}
	super.finalize();
}
}