import java.io.*;
import java.net.*;

public class EchoServer0b {
	public static void main(String[] args) throws IOException {

		ServerSocket serverSocket =	null;
		PrintWriter toSocket = null;
		BufferedReader fromSocket = null;
		
		try {
			serverSocket = new ServerSocket(4444);
		} catch	(IOException e) {
			System.err.println("!COULD NOT LISTEN ON PORT 4444");
			System.exit(1);
		}

		while (true){
			Socket clientSocket	= null;
			try {
				System.out.println("!LISTENING ON PORT 4444... ");
				// 2)
				clientSocket = serverSocket.accept();
				System.out.println("!NEW CONNECTION");
			} catch	(IOException e) {
				System.err.println("!ACCEPT FAILED");
				System.exit(1);
			}
	
			toSocket = new PrintWriter(clientSocket.getOutputStream(), true);
			fromSocket =	new	BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
			String inputLine = "";
	
			System.out.println("!WAITING FOR MESSAGE...");
			// 4)
			inputLine = fromSocket.readLine();
			System.out.println("<MESSAGE RECEIVED: " + inputLine);
			
			if (inputLine != null) {
				System.out.println(">SENDING ECHO");
				// 5)
				toSocket.println("Echo... " + inputLine);
			}
			
			System.out.println("!CLOSING CLIENT SOCKET");
			System.out.println();
			clientSocket.close();
			toSocket.close();
			fromSocket.close();
		}
	}
}