/* * Copyright 2015 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; import io.netty.util.internal.UnstableApi; import java.net.Inet4Address; import java.net.Inet6Address; import java.net.InetAddress; import java.util.Locale; import java.util.Map; /** * Default {@link HostsFileEntriesResolver} that resolves hosts file entries only once. */ @UnstableApi public final class DefaultHostsFileEntriesResolver implements HostsFileEntriesResolver { private final Map<String, Inet4Address> inet4Entries; private final Map<String, Inet6Address> inet6Entries; public DefaultHostsFileEntriesResolver() { this(HostsFileParser.parseSilently()); } // for testing purpose only DefaultHostsFileEntriesResolver(HostsFileEntries entries) { inet4Entries = entries.inet4Entries(); inet6Entries = entries.inet6Entries(); } @Override public InetAddress address(String inetHost, ResolvedAddressTypes resolvedAddressTypes) { String normalized = normalize(inetHost); switch (resolvedAddressTypes) { case IPV4_ONLY: return inet4Entries.get(normalized); case IPV6_ONLY: return inet6Entries.get(normalized); case IPV4_PREFERRED: Inet4Address inet4Address = inet4Entries.get(normalized); return inet4Address != null? inet4Address : inet6Entries.get(normalized); case IPV6_PREFERRED: Inet6Address inet6Address = inet6Entries.get(normalized); return inet6Address != null? inet6Address : inet4Entries.get(normalized); default: throw new IllegalArgumentException("Unknown ResolvedAddressTypes " + resolvedAddressTypes); } } // package-private for testing purposes String normalize(String inetHost) { return inetHost.toLowerCase(Locale.ENGLISH); } }