1. CapsEchoServer.java
2. ClientBiDirectionalSocketTest.java
3. EchoServer.java
4. InetAddressTest.java
5. MultiThreadedServer.java
6. SocketTest.java
7. ThreadedEchoHandler.java
8. TimeoutSockets.java

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;

/**
 * Server that listens on port 1999, prints out the client's message
 * (uppercase), and then sends the client's message, uppercased, back
 * to the client.
 * @author Sara Sprenkle
 */
public class CapsEchoServer {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
	    try {
		ServerSocket server = new ServerSocket(1999);
		Socket incoming = server.accept();
		
		BufferedReader br = new BufferedReader(new InputStreamReader(
									     incoming.getInputStream()));

		String line = null;

		PrintWriter out = new PrintWriter(incoming.getOutputStream());

		while ((line = br.readLine()) != null) {
		    String upperLine = line.toUpperCase();
		    System.out.println(upperLine);
		    out.println(upperLine);
		}
		
	    } catch (IOException exc) {
		System.out.println("Error:" + exc);
	    }
	}
}

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.Socket;

/**
 * This test program opens both input and output streams on the same socket -- to
 * both read from and write to the server.
 * 
 * For more on time servers: http://tf.nist.gov/tf-cgi/servers.cgi
 * 
 * @author sprenkle
 * 
 */
public class ClientBiDirectionalSocketTest {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		try {
			Socket s = new Socket("time-d.nist.gov", 13);
			BufferedReader in = new BufferedReader(new InputStreamReader(s
					.getInputStream()));
			PrintWriter out = new PrintWriter(s.getOutputStream(), true); // auto-flush
			// TODO: read from in (input received from server)
			// TODO: write to out (output send to server)

		} catch (IOException exp) {
			System.out.println("Error:" + exp);
		}
	}
}

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;

/**
 * Server listens on port 1999, echoes client's message until the
 * client enters "BYE".
 *
 * @author sprenkle 
 */
public class EchoServer {

    /**
     * @param args
     */
    public static void main(String[] args) {
	try {
	    ServerSocket server = new ServerSocket(1999);
	    // will block until a client connects
	    Socket incoming = server.accept();
	    BufferedReader in = new BufferedReader(new InputStreamReader(
									 incoming.getInputStream()));
	    PrintWriter out = new PrintWriter(incoming.getOutputStream(), true);
	    out.println("Echo Server. Type BYE to exit");
	    String line = null;
	    while ((line = in.readLine()) != null) {
		if (line.trim().equals("BYE")) {
		    break;
		}
		else {
		    out.println("Echo:" + line.trim());
		}
	    }
	    incoming.close();
	    out.close();
	} catch (IOException e) {
	    e.printStackTrace();
	}
    }
}

import java.net.InetAddress;
import java.net.UnknownHostException;

/**
 * Practice using InetAddress class
 * 
 * @author sprenkle
 * 
 */
public class InetAddressTest {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		try {
			InetAddress addr = InetAddress.getByName("www.cs.wlu.edu");
			System.out.println(addr);
			InetAddress[] addresses = InetAddress.getAllByName("www.cnn.com");
			for (InetAddress ia : addresses) {
				System.out.println(ia);
			}
			addresses = InetAddress.getAllByName("www.espn.com");
                        for (InetAddress ia : addresses) {
                                System.out.println(ia);
                        }
			InetAddress address = InetAddress.getLocalHost();
			System.out.println(address);
		} catch (UnknownHostException e) {
			e.printStackTrace();
		}
	}

}

import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;

/**
 * An example of a multi-threaded server that spawns a thread for every incoming
 * request.
 * 
 * @author sprenkle
 * 
 */
public class MultiThreadedServer {

    /**
     * @param args
     */
    public static void main(String[] args) {
	ServerSocket server;
	try {
	    server = new ServerSocket(1999);
	    while (true) {
		Socket incoming = server.accept();
		Thread clientThread = new ThreadedEchoHandler(incoming);
		clientThread.start();
	    }
	} catch (IOException e) {
	    e.printStackTrace();
	}	
    }
}

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.Socket;

/**
 * Practice using a socket to connect to a server and read from the socket.
 * 
 * @author sprenkle
 * 
 */
public class SocketTest {

	public static void main(String argv[]) {
		
		try {
			Socket socket = new Socket("time-d.nist.gov", 13);
			BufferedReader in = new BufferedReader(new InputStreamReader(socket
					.getInputStream()));

			String line = null;
			while ((line = in.readLine()) != null) {
				System.out.println(line);
			}
		} catch (IOException exc) {
			System.out.println("Error:" + exc);
		}
	}
}

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.Socket;

/**
 * Implementation of the EchoServer's handling of clients.  The
 * MultiThreadedServer delegates to this class.
 *
 * Alternatively, you could have the class implement Runnable
 * interface.  (Tradeoffs for extending Thread class versus
 * implementing Runnable interface?)
 *
 * @author sprenkle
 */
public class ThreadedEchoHandler extends Thread {
    private Socket incoming;

    public ThreadedEchoHandler(Socket incoming) {
	this.incoming = incoming;
    }

    public void run() {
	try {
	    BufferedReader in = new BufferedReader(new InputStreamReader(
									 incoming.getInputStream()));
	    PrintWriter out = new PrintWriter(incoming.getOutputStream(), true);
	    out.println("CAPS Echo Server. Type BYE to exit");
	    String line = null;
	    while ((line = in.readLine()) != null) {
		if (line.trim().equals("BYE")) {
		    break;
		}
		else {
		    out.println("Echo:" + line.trim().toUpperCase());
		}
	    }
	    incoming.close();
	    out.close();			
	} catch (IOException exc) {
	    System.out.println("Error:" + exc);
	}
    }
}

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.Socket;
import java.net.UnknownHostException;

/**
 * Demonstrates use of timeouts
 * 
 * @author sprenkle
 * 
 */
public class TimeoutSockets {

	/**
	 * @param args
	 */
	public static void main(String[] args) {

		try {
			Socket sckt1 = new Socket("host", 1998);
			sckt1.setSoTimeout(10000); // 10 second timeout

			BufferedReader in = new BufferedReader(new InputStreamReader(sckt1
					.getInputStream()));
			String line;
			while ((line = in.readLine()) != null) {
				System.out.println("Handling " + line);
			}
		} catch (UnknownHostException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}
		
	}
}