package jutil;

import java.io.*;
import java.net.*;
import jutil.*;
/**
 * Base class of all request handler slaves.
 */
public class RequestHandler extends Correspondent implements Runnable {
	/**
	 * Set this flag to false in the response method override in order to
	 * stop the handler.
	 */
	 protected boolean more = true;
	/**
	 * This constructor does not initialize inherited fields. The
	 * user must subsequently call setSocket. We need this constructor
	 * so the server can use newInstance.
	 */
	public RequestHandler() {}
	/**
	 * Initializes all fields using provided socket.
	 * @param  s  The socket provided by the server.
	 */
	public RequestHandler(Socket s) { super(s); }
	/**
	 * Initialize all fields using the socket provided.
	 * @param s  The socket provided by the server.
	 */
	public void setSocket(Socket s) {
		sock = s;
		initStreams();
	}
	/**
	 * Override this method in a subclass. The default implementation
	 * merely appends the client message to the string "echo: ".
	 * @param msg  The client's message.
	 */
	protected String response(String msg) {
		return "echo: " + msg;
	}
	/**
	 * Perpetually receives a message from the client, creates
	 * a response, then sends the response back to the client.
	 * If the message is "quit" then the handler shuts down.
	 */
	public void run() {
		while(more) {
			String msg = receive();
			System.out.println("received: " + msg);
			//if (msg == null) continue;
			if (msg.equals("quit")) break;
			msg = response(msg);
			System.out.println("sending: " + msg);
			send(msg);
		}
		close();
		System.out.println("request handler shutting down");
	}
}