// EchoClient.java
import java.io.*;
import java.net.*;

class EchoClient
{
    public static void main(String[] args) throws IOException
    {
	Socket t = new Socket(args[0], 8189); //8189 is chosen by the programmer
	String str;

	DataInputStream is = new DataInputStream(t.getInputStream());
	PrintStream out = new PrintStream(t.getOutputStream());
	DataInputStream in = new DataInputStream(System.in);

	System.out.println("Hello! Enter BYE to exit.\r");
	boolean more = true;
	while (more)
	{
	    System.out.println("type in a line : ");
	    str = in.readLine();
	    if ((str != null) && !(str.trim().equals("BYE")))
	    {
		out.println(str);
		str = is.readLine();
		System.out.println(str);
	    }
	    else
		more = false;
	}  // while
    }  // main
}

// ThreadEchoServer.java
import java.io.*;
import java.net.*;

public class ThreadEchoServer
{
    public static void main(String[] args)
    {
	int i = 0;
	try 
	{
            // port 8189 is chosen by the programmer
	    ServerSocket s = new ServerSocket(8189);

	    for (;;)
	    {
		Socket incoming = s.accept();
		i ++;
		System.out.println("Spawning " + i);
		ThreadEchoHandler t = new ThreadEchoHandler(incoming, i);
		t.start();
	    }
	}
	catch (Exception e)
	{
	    System.out.println(e);
	}
    }  // main
}   // ThreadEchoServer


// ThreadEchoHandler.java
import java.io.*;
import java.net.*;

public class ThreadEchoHandler extends Thread
{
    public ThreadEchoHandler(Socket i, int c)
    {
	incoming = i;
	counter  = c;
    }

    public void run()
    {
	try
	{
	    DataInputStream in
		= new DataInputStream(incoming.getInputStream());
	    PrintStream out
		= new PrintStream(incoming.getOutputStream());

//	    out.println("Hello! Enter BYE to exit.\r");

	    boolean done = false;
	    while (!done)
	    {
		String str = in.readLine();
		if (str == null)
		    done = true;
		else
		{
		    out.println("Echo: " + str + "\r");

		    if (str.trim().equals("BYE"))
			done = true;
		}
	    }   // while
	    incoming.close();
	}   // try
	catch (Exception e)
	{
	    System.out.println(e);
	}
    }   // run
    private Socket incoming;
    private int counter;
}