Java tutorial
/* * 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 * * 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.core.task; import java.util.concurrent.Callable; import java.util.concurrent.Future; /** * Extended interface for asynchronous {@link TaskExecutor} implementations, * offering an overloaded {@link #execute(Runnable, long)} variant with a start * timeout parameter as well support for {@link java.util.concurrent.Callable}. * * <p>Note: The {@link java.util.concurrent.Executors} class includes a set of * methods that can convert some other common closure-like objects, for example, * {@link java.security.PrivilegedAction} to {@link Callable} before executing them. * * <p>Implementing this interface also indicates that the {@link #execute(Runnable)} * method will not execute its Runnable in the caller's thread but rather * asynchronously in some other thread. * * @author Juergen Hoeller * @since 2.0.3 * @see SimpleAsyncTaskExecutor * @see org.springframework.scheduling.SchedulingTaskExecutor * @see java.util.concurrent.Callable * @see java.util.concurrent.Executors */ public interface AsyncTaskExecutor extends TaskExecutor { /** Constant that indicates immediate execution. */ long TIMEOUT_IMMEDIATE = 0; /** Constant that indicates no time limit. */ long TIMEOUT_INDEFINITE = Long.MAX_VALUE; /** * Execute the given {@code task}. * @param task the {@code Runnable} to execute (never {@code null}) * @param startTimeout the time duration (milliseconds) within which the task is * supposed to start. This is intended as a hint to the executor, allowing for * preferred handling of immediate tasks. Typical values are {@link #TIMEOUT_IMMEDIATE} * or {@link #TIMEOUT_INDEFINITE} (the default as used by {@link #execute(Runnable)}). * @throws TaskTimeoutException in case of the task being rejected because * of the timeout (i.e. it cannot be started in time) * @throws TaskRejectedException if the given task was not accepted */ void execute(Runnable task, long startTimeout); /** * Submit a Runnable task for execution, receiving a Future representing that task. * The Future will return a {@code null} result upon completion. * @param task the {@code Runnable} to execute (never {@code null}) * @return a Future representing pending completion of the task * @throws TaskRejectedException if the given task was not accepted * @since 3.0 */ Future<?> submit(Runnable task); /** * Submit a Callable task for execution, receiving a Future representing that task. * The Future will return the Callable's result upon completion. * @param task the {@code Callable} to execute (never {@code null}) * @return a Future representing pending completion of the task * @throws TaskRejectedException if the given task was not accepted * @since 3.0 */ <T> Future<T> submit(Callable<T> task); }