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

public class EchoServer0 {
	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);
		}

		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 SOCKET");
		toSocket.close();
		fromSocket.close();
		clientSocket.close();
		serverSocket.close();
	}
}