NioSocketChannel

类

io.netty.channel.socket.nio.NioSocketChannel
封装了操作java nio操作

public class NioSocketChannel extends AbstractNioByteChannel implements io.netty.channel.socket.SocketChannel { }

打开SocketChannel

public NioSocketChannel(SelectorProvider provider) {
    this(newSocket(provider));
}

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

获取SocketChannel

private final SelectableChannel ch;

protected SelectableChannel javaChannel() {
    return ch;
}


protected SocketChannel javaChannel() {
    return (SocketChannel) super.javaChannel();
}

isActive

public boolean isActive() {
        SocketChannel ch = javaChannel();
        return ch.isOpen() && ch.isConnected();
 }

isShutdown

public boolean isShutdown() {
        Socket socket = javaChannel().socket();
        return socket.isInputShutdown() && socket.isOutputShutdown() || !isActive();
    }

shutdown

private void shutdownInput0(final ChannelPromise promise) {
        try {
            shutdownInput0();
            promise.setSuccess();
        } catch (Throwable t) {
            promise.setFailure(t);
        }
    }

    private void shutdownInput0() throws Exception {
        if (PlatformDependent.javaVersion() >= 7) {
            javaChannel().shutdownInput();
        } else {
            javaChannel().socket().shutdownInput();
        }
    }

bind

protected void doBind(SocketAddress localAddress) throws Exception {
        doBind0(localAddress);
    }

    private void doBind0(SocketAddress localAddress) throws Exception {
        if (PlatformDependent.javaVersion() >= 7) {
            SocketUtils.bind(javaChannel(), localAddress);
        } else {
            SocketUtils.bind(javaChannel().socket(), localAddress);
        }
    }

connect

protected boolean doConnect(SocketAddress remoteAddress, SocketAddress localAddress) throws Exception {
        if (localAddress != null) {
            doBind0(localAddress);
        }

        boolean success = false;
        try {
            boolean connected = SocketUtils.connect(javaChannel(), remoteAddress);
            if (!connected) {
                selectionKey().interestOps(SelectionKey.OP_CONNECT);
            }
            success = true;
            return connected;
        } finally {
            if (!success) {
                doClose();
            }
        }
    }

close

    @Override
    protected void doDisconnect() throws Exception {
        doClose();
    }

    @Override
    protected void doClose() throws Exception {
        super.doClose();
        javaChannel().close();
    }