AbstractAddressResolver Class — netty Architecture

Source Code

resolver/src/main/java/io/netty/resolver/AbstractAddressResolver.java lines 34–206

public abstract class AbstractAddressResolver<T extends SocketAddress> implements AddressResolver<T> {

    private final EventExecutor executor;
    private final TypeParameterMatcher matcher;

    /**
     * @param executor the {@link EventExecutor} which is used to notify the listeners of the {@link Future} returned
     *                 by {@link #resolve(SocketAddress)}
     */
    protected AbstractAddressResolver(EventExecutor executor) {
        this.executor = checkNotNull(executor, "executor");
        this.matcher = TypeParameterMatcher.find(this, AbstractAddressResolver.class, "T");
    }

    /**
     * @param executor the {@link EventExecutor} which is used to notify the listeners of the {@link Future} returned
     *                 by {@link #resolve(SocketAddress)}
     * @param addressType the type of the {@link SocketAddress} supported by this resolver
     */
    protected AbstractAddressResolver(EventExecutor executor, Class<? extends T> addressType) {
        this.executor = checkNotNull(executor, "executor");
        this.matcher = TypeParameterMatcher.get(addressType);
    }

    /**
     * Returns the {@link EventExecutor} which is used to notify the listeners of the {@link Future} returned
     * by {@link #resolve(SocketAddress)}.
     */
    protected EventExecutor executor() {
        return executor;
    }

    @Override
    public boolean isSupported(SocketAddress address) {
        return matcher.match(address);
    }

    @Override
    public final boolean isResolved(SocketAddress address) {
        if (!isSupported(address)) {
            throw new UnsupportedAddressTypeException();
        }

        @SuppressWarnings("unchecked")
        final T castAddress = (T) address;
        return doIsResolved(castAddress);
    }

    /**
     * Invoked by {@link #isResolved(SocketAddress)} to check if the specified {@code address} has been resolved
     * already.
     */
    protected abstract boolean doIsResolved(T address);

    @Override
    public final Future<T> resolve(SocketAddress address) {
        if (!isSupported(checkNotNull(address, "address"))) {
            // Address type not supported by the resolver
            return executor().newFailedFuture(new UnsupportedAddressTypeException());
        }

        if (isResolved(address)) {
            // Resolved already; no need to perform a lookup
            @SuppressWarnings("unchecked")
            final T cast = (T) address;
            return executor.newSucceededFuture(cast);
        }

        try {
            @SuppressWarnings("unchecked")
            final T cast = (T) address;
            final Promise<T> promise = executor().newPromise();
            doResolve(cast, promise);
            return promise;
        } catch (Exception e) {
            return executor().newFailedFuture(e);
        }
    }

    @Override
    public final Future<T> resolve(SocketAddress address, Promise<T> promise) {