/*
 * Java読書会 ハンズオン
 * IPv6マルチキャスト実習
 */

package javareading.handson.ipv6udp;

import java.io.IOException;
import java.net.DatagramPacket;
import java.net.InetAddress;
import java.net.MulticastSocket;

/**
 * マルチキャスト受信クラス。
 * 「IPv6のマルチキャストソケット(UDP)を使って受信した内容と送信元を画面に出力する。
 * 
 * @author imai
 * 
 */
public class MyMulticastReceiver implements Runnable {
    private static final int DATASIZE = 512;
    private static final int TIMEOUT = 15 * 1000; // msec

    private InetAddress mcastAddress;
    private MulticastSocket socket;
    private byte[] data;

    public MyMulticastReceiver(String host, int port) throws IOException {
        mcastAddress = InetAddress.getByName(host);
        socket = new MulticastSocket(port);
        socket.joinGroup(mcastAddress);
        socket.setSoTimeout(TIMEOUT);
        data = new byte[DATASIZE];
        System.out.println("interface = " + socket.getInterface());
    }

    public void run() {
        try {
            while (true) {
                DatagramPacket packet = new DatagramPacket(data, data.length);
                socket.receive(packet);
                System.out.println(new String(data, 0, packet.getLength())
                        + " from " + packet.getAddress() + ":"
                        + packet.getPort());
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                socket.leaveGroup(mcastAddress);
            } catch (IOException e) {
                e.printStackTrace();
            }
            socket.close();
            System.out.println("exiting");
        }
    }

    public static void main(String args[]) throws IOException {
        new Thread(new MyMulticastReceiver("ff35:40:fdb4:353a:c83f:10::10",
                10101)).start();
    }
}