/*
 * @(#)TimeQuery.java	1.2 01/12/13
 * Ask a list of hosts what time it is.  Demonstrates NIO socket channels
 * (connection and reading), buffer handling, charsets, and regular
 * expressions.
 *
 * Copyright (c) 2001, 2002, Oracle and/or its affiliates. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or
 * without modification, are permitted provided that the following
 * Redistribution and use in source and binary forms, with or 
 * without modification, are permitted provided that the following 
 * conditions are met:
 *
 * -Redistributions of source code must retain the above copyright
 * 
 * -Redistributions of source code must retain the above copyright  
 * notice, this  list of conditions and the following disclaimer.
 *
 * -Redistribution in binary form must reproduct the above copyright
 * notice, this list of conditions and the following disclaimer in
 * the documentation and/or other materials provided with the
 * 
 * -Redistribution in binary form must reproduct the above copyright 
 * notice, this list of conditions and the following disclaimer in 
 * the documentation and/or other materials provided with the 
 * distribution.
 *
 * Neither the name of Oracle nor the names of
 * contributors may be used to endorse or promote products derived
 * 
 * Neither the name of Oracle nor the names of 
 * contributors may be used to endorse or promote products derived 
 * from this software without specific prior written permission.
 *
 * This software is provided "AS IS," without a warranty of any
 * kind. ALL EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND
 * WARRANTIES, INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE HEREBY
 * EXCLUDED. SUN AND ITS LICENSORS SHALL NOT BE LIABLE FOR ANY
 * DAMAGES OR LIABILITIES  SUFFERED BY LICENSEE AS A RESULT OF  OR
 * RELATING TO USE, MODIFICATION OR DISTRIBUTION OF THE SOFTWARE OR
 * ITS DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE
 * FOR ANY LOST REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT,
 * SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER
 * CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF
 * THE USE OF OR INABILITY TO USE SOFTWARE, EVEN IF SUN HAS BEEN
 * 
 * This software is provided "AS IS," without a warranty of any 
 * kind. ALL EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND 
 * WARRANTIES, INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY, 
 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE HEREBY 
 * EXCLUDED. SUN AND ITS LICENSORS SHALL NOT BE LIABLE FOR ANY 
 * DAMAGES OR LIABILITIES  SUFFERED BY LICENSEE AS A RESULT OF  OR 
 * RELATING TO USE, MODIFICATION OR DISTRIBUTION OF THE SOFTWARE OR 
 * ITS DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE 
 * FOR ANY LOST REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, 
 * SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER 
 * CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF 
 * THE USE OF OR INABILITY TO USE SOFTWARE, EVEN IF SUN HAS BEEN 
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
 *
 * You acknowledge that Software is not designed, licensed or
 * intended for use in the design, construction, operation or
 * maintenance of any nuclear facility.
 * 
 * You acknowledge that Software is not designed, licensed or 
 * intended for use in the design, construction, operation or 
 * maintenance of any nuclear facility. 
 */

import java.io.*;
import java.net.*;
import java.nio.*;
import java.nio.channels.*;
import java.nio.charset.*;
import java.util.regex.*;


public class TimeQuery {

    // The standard daytime port
    private static int DAYTIME_PORT = 13;

    // The port we'll actually use
    private static int port = DAYTIME_PORT;

    // Charset and decoder for US-ASCII
    private static Charset charset = Charset.forName("US-ASCII");
    private static CharsetDecoder decoder = charset.newDecoder();

    // Direct byte buffer for reading
    private static ByteBuffer dbuf = ByteBuffer.allocateDirect(1024);

    // Ask the given host what time it is
    //
    private static void query(String host) throws IOException {
        InetSocketAddress isa
            = new InetSocketAddress(InetAddress.getByName(host), port);
        SocketChannel sc = null;
	InetSocketAddress isa
	    = new InetSocketAddress(InetAddress.getByName(host), port);
	SocketChannel sc = null;

        try {
	try {

            // Connect
            sc = SocketChannel.open();
            sc.connect(isa);
	    // Connect
	    sc = SocketChannel.open();
	    sc.connect(isa);

            // Read the time from the remote host.  For simplicity we assume
            // that the time comes back to us in a single packet, so that we
            // only need to read once.
            dbuf.clear();
            sc.read(dbuf);
	    // Read the time from the remote host.  For simplicity we assume
	    // that the time comes back to us in a single packet, so that we
	    // only need to read once.
	    dbuf.clear();
	    sc.read(dbuf);

            // Print the remote address and the received time
            dbuf.flip();
            CharBuffer cb = decoder.decode(dbuf);
            System.out.print(isa + " : " + cb);
	    // Print the remote address and the received time
	    dbuf.flip();
	    CharBuffer cb = decoder.decode(dbuf);
	    System.out.print(isa + " : " + cb);

        } finally {
            // Make sure we close the channel (and hence the socket)
            if (sc != null)
                sc.close();
        }
	} finally {
	    // Make sure we close the channel (and hence the socket)
	    if (sc != null)
		sc.close();
	}
    }

    public static void main(String[] args) {
        if (args.length < 1) {
            System.err.println("Usage: java TimeQuery [port] host...");
            return;
        }
        int firstArg = 0;
	if (args.length < 1) {
	    System.err.println("Usage: java TimeQuery [port] host...");
	    return;
	}
	int firstArg = 0;

        // If the first argument is a string of digits then we take that
        // to be the port number
        if (Pattern.matches("[0-9]+", args[0])) {
            port = Integer.parseInt(args[0]);
            firstArg = 1;
        }
	// If the first argument is a string of digits then we take that
	// to be the port number
	if (Pattern.matches("[0-9]+", args[0])) {
	    port = Integer.parseInt(args[0]);
	    firstArg = 1;
	}

        for (int i = firstArg; i < args.length; i++) {
            String host = args[i];
            try {
                query(host);
            } catch (IOException x) {
                System.err.println(host + ": " + x);
            }
        }
	for (int i = firstArg; i < args.length; i++) {
	    String host = args[i];
	    try {
		query(host);
	    } catch (IOException x) {
		System.err.println(host + ": " + x);
	    }
	}
    }

}