org.springframework.util.concurrent.ListenableFutureTask Maven / Gradle / Ivy
/*
* Copyright 2002-2018 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.Callable;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.FutureTask;
import org.springframework.lang.Nullable;
/**
* Extension of {@link FutureTask} that implements {@link ListenableFuture}.
*
* @author Arjen Poutsma
* @since 4.0
* @param the result type returned by this Future's {@code get} method
*/
public class ListenableFutureTask extends FutureTask implements ListenableFuture {
private final ListenableFutureCallbackRegistry callbacks = new ListenableFutureCallbackRegistry<>();
/**
* Create a new {@code ListenableFutureTask} that will, upon running,
* execute the given {@link Callable}.
* @param callable the callable task
*/
public ListenableFutureTask(Callable callable) {
super(callable);
}
/**
* Create a {@code ListenableFutureTask} that will, upon running,
* execute the given {@link Runnable}, and arrange that {@link #get()}
* will return the given result on successful completion.
* @param runnable the runnable task
* @param result the result to return on successful completion
*/
public ListenableFutureTask(Runnable runnable, @Nullable T result) {
super(runnable, result);
}
@Override
public void addCallback(ListenableFutureCallback callback) {
this.callbacks.addCallback(callback);
}
@Override
public void addCallback(SuccessCallback successCallback, FailureCallback failureCallback) {
this.callbacks.addSuccessCallback(successCallback);
this.callbacks.addFailureCallback(failureCallback);
}
@Override
public CompletableFuture completable() {
CompletableFuture completable = new DelegatingCompletableFuture<>(this);
this.callbacks.addSuccessCallback(completable::complete);
this.callbacks.addFailureCallback(completable::completeExceptionally);
return completable;
}
@Override
protected void done() {
Throwable cause;
try {
T result = get();
this.callbacks.success(result);
return;
}
catch (InterruptedException ex) {
Thread.currentThread().interrupt();
return;
}
catch (ExecutionException ex) {
cause = ex.getCause();
if (cause == null) {
cause = ex;
}
}
catch (Throwable ex) {
cause = ex;
}
this.callbacks.failure(cause);
}
}