57 lines
2.0 KiB
Java
57 lines
2.0 KiB
Java
|
/*
|
||
|
* 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<DnsServerAddressStreamProvider> 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;
|
||
|
}
|
||
|
}
|