Java tutorial
/* * Copyright 2016 The Netty Project * * The Netty Project licenses this file to you under the Apache License, * version 2.0 (the "License"); you may not use this file except in compliance * with the License. You may obtain a copy of the License at: * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the * License for the specific language governing permissions and limitations * under the License. */ package io.netty.resolver.dns; import io.netty.channel.EventLoop; import io.netty.handler.codec.dns.DnsRecord; import io.netty.util.internal.UnstableApi; import java.net.InetAddress; import java.util.List; /** * A cache for DNS resolution entries. */ @UnstableApi public interface DnsCache { /** * Clears all the resolved addresses cached by this resolver. * * @see #clear(String) */ void clear(); /** * Clears the resolved addresses of the specified host name from the cache of this resolver. * * @return {@code true} if and only if there was an entry for the specified host name in the cache and * it has been removed by this method */ boolean clear(String hostname); /** * Return the cached entries for the given hostname. * @param hostname the hostname * @param additionals the additional records * @return the cached entries */ List<? extends DnsCacheEntry> get(String hostname, DnsRecord[] additionals); /** * Create a new {@link DnsCacheEntry} and cache a resolved address for a given hostname. * @param hostname the hostname * @param additionals the additional records * @param address the resolved address * @param originalTtl the TLL as returned by the DNS server * @param loop the {@link EventLoop} used to register the TTL timeout * @return The {@link DnsCacheEntry} corresponding to this cache entry. */ DnsCacheEntry cache(String hostname, DnsRecord[] additionals, InetAddress address, long originalTtl, EventLoop loop); /** * Cache the resolution failure for a given hostname. * Be aware this <strong>won't</strong> be called with timeout / cancel / transport exceptions. * * @param hostname the hostname * @param additionals the additional records * @param cause the resolution failure * @param loop the {@link EventLoop} used to register the TTL timeout * @return The {@link DnsCacheEntry} corresponding to this cache entry, or {@code null} if this cache doesn't * support caching failed responses. */ DnsCacheEntry cache(String hostname, DnsRecord[] additionals, Throwable cause, EventLoop loop); }