org.springframework.util.concurrent.ListenableFutureAdapter Maven / Gradle / Ivy
/*
* Copyright 2002-2017 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 org.springframework.util.concurrent;
import java.util.concurrent.ExecutionException;
import org.springframework.lang.Nullable;
/**
* 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.
*
* @author Arjen Poutsma
* @since 4.0
* @param the type of this {@code Future}
* @param the type of the adaptee's {@code Future}
*/
public abstract class ListenableFutureAdapter extends FutureAdapter implements ListenableFuture {
/**
* Construct a new {@code ListenableFutureAdapter} with the given adaptee.
* @param adaptee the future to adapt to
*/
protected ListenableFutureAdapter(ListenableFuture adaptee) {
super(adaptee);
}
@Override
public void addCallback(final ListenableFutureCallback callback) {
addCallback(callback, callback);
}
@Override
public void addCallback(final SuccessCallback successCallback, final FailureCallback failureCallback) {
ListenableFuture listenableAdaptee = (ListenableFuture) getAdaptee();
listenableAdaptee.addCallback(new ListenableFutureCallback() {
@Override
public void onSuccess(@Nullable S result) {
T adapted = null;
if (result != null) {
try {
adapted = adaptInternal(result);
}
catch (ExecutionException ex) {
Throwable cause = ex.getCause();
onFailure(cause != null ? cause : ex);
return;
}
catch (Throwable ex) {
onFailure(ex);
return;
}
}
successCallback.onSuccess(adapted);
}
@Override
public void onFailure(Throwable ex) {
failureCallback.onFailure(ex);
}
});
}
}