ProxyHandler Class — netty Architecture

Source Code

handler-proxy/src/main/java/io/netty/handler/proxy/ProxyHandler.java lines 40–455

public abstract class ProxyHandler extends ChannelDuplexHandler {

    private static final InternalLogger logger = InternalLoggerFactory.getInstance(ProxyHandler.class);

    /**
     * The default connect timeout: 10 seconds.
     */
    private static final long DEFAULT_CONNECT_TIMEOUT_MILLIS = 10000;

    /**
     * A string that signifies 'no authentication' or 'anonymous'.
     */
    static final String AUTH_NONE = "none";

    private final SocketAddress proxyAddress;
    private volatile SocketAddress destinationAddress;
    private volatile long connectTimeoutMillis = DEFAULT_CONNECT_TIMEOUT_MILLIS;

    private volatile ChannelHandlerContext ctx;
    private PendingWriteQueue pendingWrites;
    private boolean finished;
    private boolean suppressChannelReadComplete;
    private boolean flushedPrematurely;
    private final LazyChannelPromise connectPromise = new LazyChannelPromise();
    private Future<?> connectTimeoutFuture;
    private final ChannelFutureListener writeListener = future -> {
        if (!future.isSuccess()) {
            setConnectFailure(future.cause());
        }
    };

    protected ProxyHandler(SocketAddress proxyAddress) {
        this.proxyAddress = ObjectUtil.checkNotNull(proxyAddress, "proxyAddress");
    }

    /**
     * Returns the name of the proxy protocol in use.
     */
    public abstract String protocol();

    /**
     * Returns the name of the authentication scheme in use.
     */
    public abstract String authScheme();

    /**
     * Returns the address of the proxy server.
     */
    @SuppressWarnings("unchecked")
    public final <T extends SocketAddress> T proxyAddress() {
        return (T) proxyAddress;
    }

    /**
     * Returns the address of the destination to connect to via the proxy server.
     */
    @SuppressWarnings("unchecked")
    public final <T extends SocketAddress> T destinationAddress() {
        return (T) destinationAddress;
    }

    /**
     * Returns {@code true} if and only if the connection to the destination has been established successfully.
     */
    public final boolean isConnected() {
        return connectPromise.isSuccess();
    }

    /**
     * Returns a {@link Future} that is notified when the connection to the destination has been established
     * or the connection attempt has failed.
     */
    public final Future<Channel> connectFuture() {
        return connectPromise;
    }

    /**
     * Returns the connect timeout in millis.  If the connection attempt to the destination does not finish within
     * the timeout, the connection attempt will be failed.
     */
    public final long connectTimeoutMillis() {