public interface Executor{void execute(Runnable command); }

public interface ExecutorService extends Executor {void shutdown(); List<Runnable> shutdownNow(); boolean isShutdown(); boolean isTerminated(); boolean awaitTermination(long timeout, TimeUnit unit) throws InterruptedException; <T> Future<T> submit(Callable<T> task); <T> Future<T> submit(Runnable task, T result); Future<?> submit(Runnable task); <T> List<Future<T>> invokeAll(Collection<? extends Callable<T>> tasks) throws InterruptedException; <T> List<Future<T>> invokeAll(Collection<? extends Callable<T>> tasks, long timeout, TimeUnit unit) throws InterruptedException; <T> T invokeAny(Collection<? extends Callable<T>> tasks) throws InterruptedException, ExecutionException; <T> T invokeAny(Collection<? extends Callable<T>> tasks, long timeout, TimeUnit unit) throws InterruptedException, ExecutionException, TimeoutException; }

public class Executors {public static ExecutorService newFixedThreadPool(int nThreads) { return new ThreadPoolExecutor(nThreads, nThreads, 0L, TimeUnit.MILLISECONDS, new LinkedBlockingQueue<Runnable>()); } ... ... }

public static ExecutorService newFixedThreadPool(int nThreads)
创建固定数目线程的线程池,每当提交一个任务就创建一个线程,直到达到池的最大长度,这时线程池会保持长度不再变化.
public static ExecutorService newCachedThreadPool() 创建一个可缓存的线程池，调用execute 将重用以前构造的线程（如果线程可用）。如果现有线程没有可用的，则创建一个新线程并添加到池中。终止并从缓存中移除那些已有 60 秒钟未被使用的线程。 public static ExecutorService newSingleThreadExecutor() 创建一个单线程化的Executor,它只创建唯一的工作者线程来执行任务,如果这个线程异常结束,会有另一个取代它. public static ScheduledExecutorService newScheduledThreadPool(int corePoolSize) 创建定长线程池,支持定时及周期性的任务执行,多数情况下可用来替代Timer类。

public class ThreadPoolTest {public static void main(String[] args) { //使用动态缓存线程池,池中的线程随着任务数量的变化而变化 ExecutorService threadPool = Executors.newCachedThreadPool(); //循环产生5个任务丢给线程池 for(int i=1; i<=5; i++){ final int taskNum = i; threadPool.execute(new Runnable() { @Override public void run() { for(int j=1; j<=2; j++){ try { Thread.sleep(500); } catch (InterruptedException e) { e.printStackTrace(); } System.out.println("任务[" + taskNum + "]使用线程[" + Thread.currentThread().getName() + "]循环打印数据:" + j); } } });//end execute(..); }//end for(var i) //如果线程中任务执行完毕,没有任务需要执行了,就关闭线程池,如果不关闭,程序就不会结束,而是持续等待新的任务.  threadPool.shutdown(); } }

public interface Callable<V> {V call() throws Exception; }

import java.util.concurrent.*;public class ExecutorTest implements Callable { @SuppressWarnings("unchecked") public static void main(String[] args) throws Exception { //创建缓存线程池 ExecutorService pool = Executors.newCachedThreadPool(); //指定线程,获取线程返回结果 Future returnV = pool.submit(new ExecutorTest()); //获取线程返回结果 System.out.println("" + returnV.get().toString()); //关闭线程池  pool.shutdown(); } @Override public Object call() throws Exception { for(int i=1; i<=5; i++){ Thread.sleep (500); System.out .println(Thread.currentThread().getName()+" print value " +i); } return "Multiple Thread Implements Callable"; } }