// // ======================================================================== // Copyright (c) 1995-2014 Mort Bay Consulting Pty. Ltd. // ------------------------------------------------------------------------ // All rights reserved. This program and the accompanying materials // are made available under the terms of the Eclipse Public License v1.0 // and Apache License v2.0 which accompanies this distribution. // // The Eclipse Public License is available at // http://www.eclipse.org/legal/epl-v10.html // // The Apache License v2.0 is available at // http://www.opensource.org/licenses/apache2.0.php // // You may elect to redistribute this code under either of these licenses. // ======================================================================== // package org.eclipse.jetty.util; import java.net.InetSocketAddress; import java.net.SocketAddress; import java.nio.channels.UnresolvedAddressException; import java.util.concurrent.Executor; import java.util.concurrent.TimeUnit; import java.util.concurrent.TimeoutException; import java.util.concurrent.atomic.AtomicBoolean; import org.eclipse.jetty.util.log.Log; import org.eclipse.jetty.util.log.Logger; import org.eclipse.jetty.util.thread.Scheduler; /** * Creates asynchronously {@link SocketAddress} instances, returning them through a {@link Promise}, * in order to avoid blocking on DNS lookup. *
* {@link InetSocketAddress#InetSocketAddress(String, int)} attempts to perform a DNS resolution of * the host name, and this may block for several seconds. * This class creates the {@link InetSocketAddress} in a separate thread and provides the result * through a {@link Promise}, with the possibility to specify a timeout for the operation. * * Example usage: ** SocketAddressResolver resolver = new SocketAddressResolver(executor, scheduler); * resolver.resolve("www.google.com", 80, new Promise<SocketAddress>() * { * public void succeeded(SocketAddress result) * { * // The address was resolved * } * * public void failed(Throwable failure) * { * // The address resolution failed * } * }); **/ public class SocketAddressResolver { private static final Logger LOG = Log.getLogger(SocketAddressResolver.class); private final Executor executor; private final Scheduler scheduler; private final long timeout; /** * Creates a new instance with the given executor (to perform DNS resolution in a separate thread), * the given scheduler (to cancel the operation if it takes too long) and the given timeout, in milliseconds. * * @param executor the thread pool to use to perform DNS resolution in pooled threads * @param scheduler the scheduler to schedule tasks to cancel DNS resolution if it takes too long * @param timeout the timeout, in milliseconds, for the DNS resolution to complete */ public SocketAddressResolver(Executor executor, Scheduler scheduler, long timeout) { this.executor = executor; this.scheduler = scheduler; this.timeout = timeout; } public Executor getExecutor() { return executor; } public Scheduler getScheduler() { return scheduler; } public long getTimeout() { return timeout; } /** * Resolves the given host and port, returning a {@link SocketAddress} through the given {@link Promise} * with the default timeout. * * @param host the host to resolve * @param port the port of the resulting socket address * @param promise the callback invoked when the resolution succeeds or fails * @see #resolve(String, int, long, Promise) */ public void resolve(String host, int port, Promise