netty5/resolver-dns/src/main/java/io/netty/resolver/dns/DnsCacheEntry.java
Scott Mitchell 566566db3a Decouple DnsCache and DnsCacheEntry
Motivation:
DnsCache (an interface) is coupled to DnsCacheEntry (a final class). This means that DnsCache implementations can't implement their own DnsCacheEntry objects if the default behavior isn't appropriate.

Modifications:
- DnsCacheEntry should be moved to DefaultDnsCache as it is an implementation detail
- DnsCache#cache(..) should return a new DnsCacheEntry
- The methods which from DnsCacheEntry that were used outside the scope of DefaultDnsCache should be moved into an interface

Result:
DnsCache is more extensible and not tightly coupled to a default implementation of DnsCacheEntry.
2017-08-21 11:15:27 -07:00

41 lines
1.3 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.net.InetAddress;
/**
* Represents the results from a previous DNS query which can be cached.
*/
@UnstableApi
public interface DnsCacheEntry {
/**
* Get the resolved address.
* <p>
* This may be null if the resolution failed, and in that case {@link #cause()} will describe the failure.
* @return the resolved address.
*/
InetAddress address();
/**
* If the DNS query failed this will provide the rational.
* @return the rational for why the DNS query failed, or {@code null} if the query hasn't failed.
*/
Throwable cause();
}