Create DatagramSocket Server - Java Network

Java examples for Network:UDP

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Description

Create DatagramSocket Server

Demo Code

import java.io.*;
import java.net.*;
import java.util.*;
class MulticastServer {
    public static void main(String[] args) throws java.io.IOException {
        new MulticastServerThread().start();
    }//from w w  w . j  a  v a  2  s.  c  o m
}
class QuoteServerThread extends Thread {

    protected DatagramSocket socket = null;
    protected BufferedReader in = null;
    protected boolean moreQuotes = true;

    public QuoteServerThread() throws IOException {
        this("QuoteServerThread");
    }

    public QuoteServerThread(String name) throws IOException {
        super(name);
        socket = new DatagramSocket(4445);

        try {
            in = new BufferedReader(new FileReader("one-liners.txt"));
        } catch (FileNotFoundException e) {
            System.err
                    .println("Could not open quote file. Serving time instead.");
        }
    }

    public void run() {

        while (moreQuotes) {
            try {
                byte[] buf = new byte[256];

                // receive request
                DatagramPacket packet = new DatagramPacket(buf, buf.length);
                socket.receive(packet);

                // figure out response
                String dString = null;
                if (in == null)
                    dString = new Date().toString();
                else
                    dString = getNextQuote();

                buf = dString.getBytes();

                // send the response to the client at "address" and "port"
                InetAddress address = packet.getAddress();
                int port = packet.getPort();
                packet = new DatagramPacket(buf, buf.length, address, port);
                socket.send(packet);
            } catch (IOException e) {
                e.printStackTrace();
                moreQuotes = false;
            }
        }
        socket.close();
    }

    protected String getNextQuote() {
        String returnValue = null;
        try {
            if ((returnValue = in.readLine()) == null) {
                in.close();
                moreQuotes = false;
                returnValue = "No more quotes. Goodbye.";
            }
        } catch (IOException e) {
            returnValue = "IOException occurred in server.";
        }
        return returnValue;
    }
}

public class MulticastServerThread extends QuoteServerThread {

    private long FIVE_SECONDS = 5000;

    public MulticastServerThread() throws IOException {
        super("MulticastServerThread");
    }

    public void run() {
        while (moreQuotes) {
            try {
                byte[] buf = new byte[256];

                // construct quote
                String dString = null;
                if (in == null)
                    dString = new Date().toString();
                else
                    dString = getNextQuote();
                buf = dString.getBytes();

                // send it
                InetAddress group = InetAddress.getByName("230.0.0.1");
                DatagramPacket packet = new DatagramPacket(buf, buf.length,
                        group, 4446);
                socket.send(packet);

                // sleep for a while
                try {
                    sleep((long) (Math.random() * FIVE_SECONDS));
                } catch (InterruptedException e) {
                }
            } catch (IOException e) {
                e.printStackTrace();
                moreQuotes = false;
            }
        }
        socket.close();
    }
}

/*
 * Copyright (c) 1995, 2008, 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 conditions
 * are met:
 *
 *   - Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *
 *   - Redistributions in binary form must reproduce 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 or the names of its
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

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