io.netty.resolver.dns.RoundRobinDnsAddressResolverGroup Maven / Gradle / Ivy
/*
* 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.ChannelFactory;
import io.netty.channel.EventLoop;
import io.netty.channel.socket.DatagramChannel;
import io.netty.resolver.AddressResolver;
import io.netty.resolver.AddressResolverGroup;
import io.netty.resolver.NameResolver;
import io.netty.resolver.RoundRobinInetAddressResolver;
import io.netty.util.internal.UnstableApi;
import java.net.InetAddress;
import java.net.InetSocketAddress;
/**
* A {@link AddressResolverGroup} of {@link DnsNameResolver}s that supports random selection of destination addresses if
* multiple are provided by the nameserver. This is ideal for use in applications that use a pool of connections, for
* which connecting to a single resolved address would be inefficient.
*/
@UnstableApi
public class RoundRobinDnsAddressResolverGroup extends DnsAddressResolverGroup {
public RoundRobinDnsAddressResolverGroup(
Class channelType,
DnsServerAddressStreamProvider nameServerProvider) {
super(channelType, nameServerProvider);
}
public RoundRobinDnsAddressResolverGroup(
ChannelFactory channelFactory,
DnsServerAddressStreamProvider nameServerProvider) {
super(channelFactory, nameServerProvider);
}
/**
* We need to override this method, not
* {@link #newNameResolver(EventLoop, ChannelFactory, DnsServerAddressStreamProvider)},
* because we need to eliminate possible caching of {@link io.netty.resolver.NameResolver#resolve}
* by {@link InflightNameResolver} created in
* {@link #newResolver(EventLoop, ChannelFactory, DnsServerAddressStreamProvider)}.
*/
@Override
protected final AddressResolver newAddressResolver(EventLoop eventLoop,
NameResolver resolver)
throws Exception {
return new RoundRobinInetAddressResolver(eventLoop, resolver).asAddressResolver();
}
}