com.barchart.netty.server.stream.MulticastTransceiver.java Source code

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Here is the source code for com.barchart.netty.server.stream.MulticastTransceiver.java

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/**
 * Copyright (C) 2011-2014 Barchart, Inc. <http://www.barchart.com/>
 *
 * All rights reserved. Licensed under the OSI BSD License.
 *
 * http://www.opensource.org/licenses/bsd-license.php
 */
package com.barchart.netty.server.stream;

import io.netty.bootstrap.Bootstrap;
import io.netty.channel.Channel;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelOption;
import io.netty.channel.socket.nio.NioDatagramChannel;
import io.netty.util.NetUtil;
import io.netty.util.concurrent.Future;
import io.netty.util.concurrent.GenericFutureListener;

import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.NetworkInterface;
import java.net.SocketAddress;

import com.barchart.netty.server.base.AbstractServer;

/**
 * A multicast transceiver that can send and receive messages in a UDP multicast
 * group.
 */
public class MulticastTransceiver extends AbstractServer<MulticastTransceiver, Bootstrap> {

    protected InetSocketAddress multicast;

    /**
     * The multicast group address.
     */
    public MulticastTransceiver multicast(final InetSocketAddress address) {
        multicast = address;
        return this;
    }

    @Override
    protected Bootstrap bootstrap() {

        final Bootstrap bootstrap = new Bootstrap() //
                .group(defaultGroup) //
                .channel(NioDatagramChannel.class) //
                .handler(new ServerChannelInitializer()) //
                .option(ChannelOption.SO_REUSEADDR, true) //
                .option(ChannelOption.IP_MULTICAST_TTL, 3) //
                .option(ChannelOption.SO_SNDBUF, 262144) //
                .option(ChannelOption.SO_RCVBUF, 262144);

        if (bootstrapInit != null) {
            bootstrapInit.initBootstrap(bootstrap);
        }

        return bootstrap;

    }

    /**
     * Join the multicast group address using the network interface associated
     * with the given address.
     */
    @Override
    public ChannelFuture listen(final SocketAddress address) {

        if (pipelineInit == null) {
            throw new IllegalStateException("No pipeline initializer has been provided, server would do nothing");
        }

        // Kinda hacky, need to override bootstrap params based on passed
        // address

        final ChannelFuture future = bootstrap() //
                .option(ChannelOption.IP_MULTICAST_IF, bindInterface((InetSocketAddress) address)) //
                .localAddress(multicast.getPort()) //
                .remoteAddress(multicast) //
                .bind();

        future.addListener(new GenericFutureListener<ChannelFuture>() {

            @Override
            public void operationComplete(final ChannelFuture future) throws Exception {

                if (future.isSuccess()) {

                    final NioDatagramChannel channel = (NioDatagramChannel) future.channel();

                    channel.joinGroup(multicast, channel.config().getOption(ChannelOption.IP_MULTICAST_IF));

                }

            }

        });

        serverChannels.add(future.channel());

        return future;

    }

    @Override
    public Future<MulticastTransceiver> shutdown() {

        for (final Channel c : serverChannels) {

            final NioDatagramChannel dc = (NioDatagramChannel) c;

            final InetSocketAddress multicast = dc.remoteAddress();

            dc.leaveGroup(multicast, dc.config().getOption(ChannelOption.IP_MULTICAST_IF));

        }

        return super.shutdown();

    }

    /**
     * Valid interface or loop back interface for error.
     */
    protected NetworkInterface bindInterface(final InetSocketAddress local) {

        try {

            final InetAddress address = local.getAddress();

            final NetworkInterface iface = NetworkInterface.getByInetAddress(address);

            if (iface == null) {
                throw new IllegalArgumentException("address is not assigned to any iterface : " + address);
            }

            return iface;

        } catch (final Throwable e) {
            return NetUtil.LOOPBACK_IF;
        }

    }

}