java.util.concurrent.ExecutorService接口是Executor接口的子接口,并添加了管理生命周期的功能,包括单个任务和执行程序本身.
Sr.No. | 方法&说明 |
---|---|
1 | boolean awaitTermination(long timeout,TimeUnit unit) 阻止所有任务在关闭请求完成后执行,或发生超时,或者当前线程被中断,以先发生者为准第一个. |
2 | <T> List<Future<T>> invokeAll(Collection<? extends Callable<T>> tasks) 执行给定的任务,返回一个Futures列表,保存完整后的状态和结果. |
3 | <T> List<Future<T>> invokeAll(Collection<? extends Callable<T>> tasks, long timeout, TimeUnit unit) 执行给定的任务,返回持有其状态和结果的Futures列表当所有完成或超时到期时,以先发生者为准. |
4 | < T> T invokeAny(Collection<?extends Callable< T>> tasks) 执行给定的任务,返回已成功完成的任务的结果(即,不抛出异常),如果有的话. |
5 | < T> T invokeAny(Collection<?extends Callable< T>> tasks,long timeout,TimeUnit unit) 执行给定的任务,返回已成功完成的任务的结果(即,没有抛出异常),如果在给定的超时之前有任何超时. |
6 | boolean isShutdown() 如果此执行程序已关闭,则返回true. |
7 | boolean isTerminated() 如果关闭后所有任务都已完成,则返回true. |
8 | void shutdown() 启动有序关机执行之前提交的任务,但不会接受任何新任务. |
9 | List<Runnable> shutdownNow() 尝试停止所有正在执行的任务,暂停等待任务的处理,并返回等待执行的任务列表. |
10 | <T> Future<T> submit(Callable<T> task) 提交值返回任务以执行并返回表示任务挂起结果的Future. |
11 | Future<?> submit(Runnable task) 提交Runnable任务执行并返回表示该任务的Future. |
12 | <T> Future<T> submit(Runnable task, T result) 提交Runnable任务执行并返回表示该任务的Future. |
以下TestThread程序显示在基于线程的环境中使用ExecutorService接口.
import java.util.concurrent.ExecutorService; import java.util.concurrent.Executors; import java.util.concurrent.TimeUnit; public class TestThread { public static void main(final String[] arguments) throws InterruptedException { ExecutorService executor = Executors.newSingleThreadExecutor(); try { executor.submit(new Task()); System.out.println("Shutdown executor"); executor.shutdown(); executor.awaitTermination(5, TimeUnit.SECONDS); } catch (InterruptedException e) { System.err.println("tasks interrupted"); } finally { if (!executor.isTerminated()) { System.err.println("cancel non-finished tasks"); } executor.shutdownNow(); System.out.println("shutdown finished"); } } static class Task implements Runnable { public void run() { try { Long duration = (long) (Math.random() * 20); System.out.println("Running Task!"); TimeUnit.SECONDS.sleep(duration); } catch (InterruptedException e) { e.printStackTrace(); } } } }
这将产生以下结果.
Shutdown executor Running Task! shutdown finished cancel non-finished tasks java.lang.InterruptedException: sleep interrupted at java.lang.Thread.sleep(Native Method) at java.lang.Thread.sleep(Thread.java:302) at java.util.concurrent.TimeUnit.sleep(TimeUnit.java:328) at TestThread$Task.run(TestThread.java:39) at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:439) at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303) at java.util.concurrent.FutureTask.run(FutureTask.java:138) at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:895) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:918) at java.lang.Thread.run(Thread.java:662)