io.netty.resolver.dns.MultiDnsServerAddressStreamProvider Maven / Gradle / Ivy
/*
* Copyright 2017 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.util.internal.UnstableApi;
import java.util.List;
/**
* A {@link DnsServerAddressStreamProvider} which iterates through a collection of
* {@link DnsServerAddressStreamProvider} until the first non-{@code null} result is found.
*/
@UnstableApi
public final class MultiDnsServerAddressStreamProvider implements DnsServerAddressStreamProvider {
private final DnsServerAddressStreamProvider[] providers;
/**
* Create a new instance.
* @param providers The providers to use for DNS resolution. They will be queried in order.
*/
public MultiDnsServerAddressStreamProvider(List providers) {
this.providers = providers.toArray(new DnsServerAddressStreamProvider[0]);
}
/**
* Create a new instance.
* @param providers The providers to use for DNS resolution. They will be queried in order.
*/
public MultiDnsServerAddressStreamProvider(DnsServerAddressStreamProvider... providers) {
this.providers = providers.clone();
}
@Override
public DnsServerAddressStream nameServerAddressStream(String hostname) {
for (DnsServerAddressStreamProvider provider : providers) {
DnsServerAddressStream stream = provider.nameServerAddressStream(hostname);
if (stream != null) {
return stream;
}
}
return null;
}
}