1 /* 2 * Copyright 2017 The Netty Project 3 * 4 * The Netty Project licenses this file to you under the Apache License, 5 * version 2.0 (the "License"); you may not use this file except in compliance 6 * with the License. You may obtain a copy of the License at: 7 * 8 * https://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 12 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the 13 * License for the specific language governing permissions and limitations 14 * under the License. 15 */ 16 package io.netty.resolver.dns; 17 18 /** 19 * Provides an opportunity to override which {@link DnsServerAddressStream} is used to resolve a specific hostname. 20 * <p> 21 * For example this can be used to represent <a href="https://linux.die.net/man/5/resolver">/etc/resolv.conf</a> and 22 * <a href="https://developer.apple.com/legacy/library/documentation/Darwin/Reference/ManPages/man5/resolver.5.html"> 23 * /etc/resolver</a>. 24 */ 25 public interface DnsServerAddressStreamProvider { 26 /** 27 * Ask this provider for the name servers to query for {@code hostname}. 28 * @param hostname The hostname for which to lookup the DNS server addressed to use. 29 * If this is the final {@link DnsServerAddressStreamProvider} to be queried then generally empty 30 * string or {@code '.'} correspond to the default {@link DnsServerAddressStream}. 31 * @return The {@link DnsServerAddressStream} which should be used to resolve {@code hostname}. 32 */ 33 DnsServerAddressStream nameServerAddressStream(String hostname); 34 }