org.springframework.util.concurrent.FutureUtils Maven / Gradle / Ivy
/*
* Copyright 2002-2022 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
*
* https://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.CompletionException;
import java.util.concurrent.Executor;
import java.util.concurrent.ForkJoinPool;
import java.util.function.Supplier;
import org.springframework.util.Assert;
/**
* Convenience utilities for working with {@link java.util.concurrent.Future}
* and implementations.
*
* @author Arjen Poutsma
* @since 6.0
*/
public abstract class FutureUtils {
/**
* Return a new {@code CompletableFuture} that is asynchronously completed
* by a task running in the {@link ForkJoinPool#commonPool()} with
* the value obtained by calling the given {@code Callable}.
* @param callable a function that returns the value to be used, or throws
* an exception
* @return the new CompletableFuture
* @see CompletableFuture#supplyAsync(Supplier)
*/
public static CompletableFuture callAsync(Callable callable) {
Assert.notNull(callable, "Callable must not be null");
CompletableFuture result = new CompletableFuture<>();
return result.completeAsync(toSupplier(callable, result));
}
/**
* Return a new {@code CompletableFuture} that is asynchronously completed
* by a task running in the given executor with the value obtained
* by calling the given {@code Callable}.
* @param callable a function that returns the value to be used, or throws
* an exception
* @param executor the executor to use for asynchronous execution
* @return the new CompletableFuture
* @see CompletableFuture#supplyAsync(Supplier, Executor)
*/
public static CompletableFuture callAsync(Callable callable, Executor executor) {
Assert.notNull(callable, "Callable must not be null");
Assert.notNull(executor, "Executor must not be null");
CompletableFuture result = new CompletableFuture<>();
return result.completeAsync(toSupplier(callable, result), executor);
}
private static Supplier toSupplier(Callable callable, CompletableFuture result) {
return () -> {
try {
return callable.call();
}
catch (Exception ex) {
// wrap the exception just like CompletableFuture::supplyAsync does
result.completeExceptionally((ex instanceof CompletionException) ? ex : new CompletionException(ex));
return null;
}
};
}
}