JdpBroadcaster.java 文件源码

/**
 * Create a new broadcaster
 *
 * @param address - multicast group address
 * @param srcAddress - address of interface we should use to broadcast.
 * @param port - udp port to use
 * @param ttl - packet ttl
 * @throws IOException
 */
public JdpBroadcaster(InetAddress address, InetAddress srcAddress, int port, int ttl)
        throws IOException, JdpException {
    this.addr = address;
    this.port = port;

    ProtocolFamily family = (address instanceof Inet6Address)
            ? StandardProtocolFamily.INET6 : StandardProtocolFamily.INET;

    channel = DatagramChannel.open(family);
    channel.setOption(StandardSocketOptions.SO_REUSEADDR, true);
    channel.setOption(StandardSocketOptions.IP_MULTICAST_TTL, ttl);

    // with srcAddress equal to null, this constructor do exactly the same as
    // if srcAddress is not passed
    if (srcAddress != null) {
        // User requests particular interface to bind to
        NetworkInterface interf = NetworkInterface.getByInetAddress(srcAddress);
        try {
            channel.bind(new InetSocketAddress(srcAddress, 0));
        } catch (UnsupportedAddressTypeException ex) {
            throw new JdpException("Unable to bind to source address");
        }
        channel.setOption(StandardSocketOptions.IP_MULTICAST_IF, interf);
    }
}