io.netty.resolver.AbstractAddressResolver Maven / Gradle / Ivy
/*
* Copyright 2015 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;
import io.netty.util.concurrent.EventExecutor;
import io.netty.util.concurrent.Future;
import io.netty.util.concurrent.Promise;
import io.netty.util.internal.TypeParameterMatcher;
import io.netty.util.internal.UnstableApi;
import java.net.SocketAddress;
import java.nio.channels.UnsupportedAddressTypeException;
import java.util.Collections;
import java.util.List;
import static io.netty.util.internal.ObjectUtil.checkNotNull;
/**
* A skeletal {@link AddressResolver} implementation.
*/
@UnstableApi
public abstract class AbstractAddressResolver implements AddressResolver {
private final EventExecutor executor;
private final TypeParameterMatcher matcher;
/**
* @param executor the {@link EventExecutor} which is used to notify the listeners of the {@link Future} returned
* by {@link #resolve(SocketAddress)}
*/
protected AbstractAddressResolver(EventExecutor executor) {
this.executor = checkNotNull(executor, "executor");
matcher = TypeParameterMatcher.find(this, AbstractAddressResolver.class, "T");
}
/**
* @param executor the {@link EventExecutor} which is used to notify the listeners of the {@link Future} returned
* by {@link #resolve(SocketAddress)}
* @param addressType the type of the {@link SocketAddress} supported by this resolver
*/
protected AbstractAddressResolver(EventExecutor executor, Class addressType) {
this.executor = checkNotNull(executor, "executor");
matcher = TypeParameterMatcher.get(addressType);
}
/**
* Returns the {@link EventExecutor} which is used to notify the listeners of the {@link Future} returned
* by {@link #resolve(SocketAddress)}.
*/
protected EventExecutor executor() {
return executor;
}
@Override
public boolean isSupported(SocketAddress address) {
return matcher.match(address);
}
@Override
public final boolean isResolved(SocketAddress address) {
if (!isSupported(address)) {
throw new UnsupportedAddressTypeException();
}
@SuppressWarnings("unchecked")
final T castAddress = (T) address;
return doIsResolved(castAddress);
}
/**
* Invoked by {@link #isResolved(SocketAddress)} to check if the specified {@code address} has been resolved
* already.
*/
protected abstract boolean doIsResolved(T address);
@Override
public final Future resolve(SocketAddress address) {
if (!isSupported(checkNotNull(address, "address"))) {
// Address type not supported by the resolver
return executor().newFailedFuture(new UnsupportedAddressTypeException());
}
if (isResolved(address)) {
// Resolved already; no need to perform a lookup
@SuppressWarnings("unchecked")
final T cast = (T) address;
return executor.newSucceededFuture(cast);
}
try {
@SuppressWarnings("unchecked")
final T cast = (T) address;
final Promise promise = executor().newPromise();
doResolve(cast, promise);
return promise;
} catch (Exception e) {
return executor().newFailedFuture(e);
}
}
@Override
public final Future resolve(SocketAddress address, Promise promise) {
checkNotNull(address, "address");
checkNotNull(promise, "promise");
if (!isSupported(address)) {
// Address type not supported by the resolver
return promise.setFailure(new UnsupportedAddressTypeException());
}
if (isResolved(address)) {
// Resolved already; no need to perform a lookup
@SuppressWarnings("unchecked")
final T cast = (T) address;
return promise.setSuccess(cast);
}
try {
@SuppressWarnings("unchecked")
final T cast = (T) address;
doResolve(cast, promise);
return promise;
} catch (Exception e) {
return promise.setFailure(e);
}
}
@Override
public final Future> resolveAll(SocketAddress address) {
if (!isSupported(checkNotNull(address, "address"))) {
// Address type not supported by the resolver
return executor().newFailedFuture(new UnsupportedAddressTypeException());
}
if (isResolved(address)) {
// Resolved already; no need to perform a lookup
@SuppressWarnings("unchecked")
final T cast = (T) address;
return executor.newSucceededFuture(Collections.singletonList(cast));
}
try {
@SuppressWarnings("unchecked")
final T cast = (T) address;
final Promise> promise = executor().newPromise();
doResolveAll(cast, promise);
return promise;
} catch (Exception e) {
return executor().newFailedFuture(e);
}
}
@Override
public final Future> resolveAll(SocketAddress address, Promise> promise) {
checkNotNull(address, "address");
checkNotNull(promise, "promise");
if (!isSupported(address)) {
// Address type not supported by the resolver
return promise.setFailure(new UnsupportedAddressTypeException());
}
if (isResolved(address)) {
// Resolved already; no need to perform a lookup
@SuppressWarnings("unchecked")
final T cast = (T) address;
return promise.setSuccess(Collections.singletonList(cast));
}
try {
@SuppressWarnings("unchecked")
final T cast = (T) address;
doResolveAll(cast, promise);
return promise;
} catch (Exception e) {
return promise.setFailure(e);
}
}
/**
* Invoked by {@link #resolve(SocketAddress)} to perform the actual name
* resolution.
*/
protected abstract void doResolve(T unresolvedAddress, Promise promise) throws Exception;
/**
* Invoked by {@link #resolveAll(SocketAddress)} to perform the actual name
* resolution.
*/
protected abstract void doResolveAll(T unresolvedAddress, Promise> promise) throws Exception;
@Override
public void close() { }
}