NioDatagramChannel Class — netty Architecture

Source Code

transport/src/main/java/io/netty/channel/socket/nio/NioDatagramChannel.java lines 65–628

public final class NioDatagramChannel
        extends AbstractNioMessageChannel implements io.netty.channel.socket.DatagramChannel {

    private static final ChannelMetadata METADATA = new ChannelMetadata(true, 16);
    private static final SelectorProvider DEFAULT_SELECTOR_PROVIDER = SelectorProvider.provider();
    private static final String EXPECTED_TYPES =
            " (expected: " + StringUtil.simpleClassName(DatagramPacket.class) + ", " +
            StringUtil.simpleClassName(AddressedEnvelope.class) + '<' +
            StringUtil.simpleClassName(ByteBuf.class) + ", " +
            StringUtil.simpleClassName(SocketAddress.class) + ">, " +
            StringUtil.simpleClassName(ByteBuf.class) + ')';

    private final DatagramChannelConfig config;

    private Map<InetAddress, List<MembershipKey>> memberships;

    /**
     *  Use the {@link SelectorProvider} to open {@link DatagramChannel} and so remove condition in
     *  {@link SelectorProvider#provider()} which is called by each DatagramChannel.open() otherwise.
     * <p>
     *  See <a href="https://github.com/netty/netty/issues/2308">#2308</a>.
     */
    private static DatagramChannel newSocket(SelectorProvider provider) {
        try {
            return provider.openDatagramChannel();
        } catch (IOException e) {
            throw new ChannelException("Failed to open a socket.", e);
        }
    }

    private static DatagramChannel newSocket(SelectorProvider provider, SocketProtocolFamily ipFamily) {
        if (ipFamily == null) {
            return newSocket(provider);
        }

        try {
            return provider.openDatagramChannel(ipFamily.toJdkFamily());
        } catch (IOException e) {
            throw new ChannelException("Failed to open a socket.", e);
        }
    }

    /**
     * Create a new instance which will use the Operation Systems default {@link SocketProtocolFamily}.
     */
    public NioDatagramChannel() {
        this(newSocket(DEFAULT_SELECTOR_PROVIDER));
    }

    /**
     * Create a new instance using the given {@link SelectorProvider}
     * which will use the Operation Systems default {@link SocketProtocolFamily}.
     */
    public NioDatagramChannel(SelectorProvider provider) {
        this(newSocket(provider));
    }

    /**
     * Create a new instance using the given {@link InternetProtocolFamily}. If {@code null} is used it will depend
     * on the Operation Systems default which will be chosen.
     *
     * @deprecated use {@link NioDatagramChannel#NioDatagramChannel(SocketProtocolFamily)}
     */
    @Deprecated
    public NioDatagramChannel(InternetProtocolFamily ipFamily) {
        this(ipFamily == null ? null : ipFamily.toSocketProtocolFamily());
    }

    /**
     * Create a new instance using the given {@link SocketProtocolFamily}. If {@code null} is used it will depend
     * on the Operation Systems default which will be chosen.
     */
    public NioDatagramChannel(SocketProtocolFamily protocolFamily) {
        this(newSocket(DEFAULT_SELECTOR_PROVIDER, protocolFamily));
    }

    /**
     * Create a new instance using the given {@link SelectorProvider} and {@link InternetProtocolFamily}.
     * If {@link InternetProtocolFamily} is {@code null} it will depend on the Operation Systems default
     * which will be chosen.
     *