/*
* Copyright 2002-2013 the original author or authors.
*
* Licensed 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 com.xiongyingqi.util.concurrent;
import java.util.concurrent.ExecutionException;
/**
* Abstract class that adapts a {@link ListenableFuture} parameterized over S into a
* {@code ListenableFuture} parameterized over T. All methods are delegated to the
* adaptee, where {@link #get()}, {@link #get(long, java.util.concurrent.TimeUnit)}, and
* {@link ListenableFutureCallback#onSuccess(Object)} call {@link #adapt(Object)} on the
* adaptee's result.
*
* @param <T> the type of this {@code Future}
* @param <S> the type of the adaptee's {@code Future}
* @author Arjen Poutsma
* @since 4.0
*/
public abstract class ListenableFutureAdapter<T, S> extends FutureAdapter<T, S>
implements ListenableFuture<T> {
/**
* Constructs a new {@code ListenableFutureAdapter} with the given adaptee.
*
* @param adaptee the future to adaptee to
*/
protected ListenableFutureAdapter(ListenableFuture<S> adaptee) {
super(adaptee);
}
@Override
public void addCallback(final ListenableFutureCallback<? super T> callback) {
ListenableFuture<S> listenableAdaptee = (ListenableFuture<S>) getAdaptee();
listenableAdaptee.addCallback(new ListenableFutureCallback<S>() {
@Override
public void onSuccess(S result) {
try {
callback.onSuccess(adaptInternal(result));
} catch (ExecutionException ex) {
Throwable cause = ex.getCause();
onFailure(cause != null ? cause : ex);
} catch (Throwable t) {
onFailure(t);
}
}
@Override
public void onFailure(Throwable t) {
callback.onFailure(t);
}
});
}
}