java 线程简单例子

xiaoxiao2021-11-05 81

本片文章以Java多线程简单实力为主，全部的例子选自java 编程思想第四版，全部都是自己手动对书编写，如有疑问请直接留言。

import java.util.ArrayList; import java.util.concurrent.Callable; import java.util.concurrent.ExecutionException; import java.util.concurrent.ExecutorService; import java.util.concurrent.Executors; import java.util.concurrent.Future; import java.util.concurrent.SynchronousQueue; import java.util.concurrent.ThreadFactory; import java.util.concurrent.ThreadPoolExecutor; import java.util.concurrent.TimeUnit; /** * * * 并发编程使我们可以将程序划分为多个分离的、独立运行的任务。通过使用多线程机制， * 这些独立任务（也被称为子任务）中的每一个都将由执行线程来驱动。 * 一个线程就是在进程中的一个单一的顺序控制流，因此，单个进程可以拥有多个并发执行的任务， * 但是你的程序使得每个任务都好像有其自己的CPU一样。其底层机制是切分CPU时间，但通常你不需要考虑它。 * * @create @author Henry @date 2016-11-16 重新查看Java编程思想线程部分。 */ public class MainThread { /** * * 单独跑run方法， * * @create @author Henry @date 2016-11-16 * 结果如下： * #0(9), #0(8), #0(7), #0(6), #0(5), #0(4), #0(3), #0(2), #0(1), * #0(Liftoff), * @param args */ public static void main1(String[] args) { LiftOff lauch = new LiftOff(); lauch.run(); } /** * * 将其付给Thread跑 * * @create @author Henry @date 2016-11-16 * 90%结果如下： * Waiting for LiftOff * #0(9), #0(8), #0(7), #0(6), #0(5), #0(4), #0(3), #0(2), #0(1), * #0(Liftoff), * @param args */ public static void main2(String[] args) { Thread thread = new Thread(new LiftOff()); thread.start(); System.out.println("Waiting for LiftOff"); } /** * * 启动5个子线程 * * 输出说明不同任务的执行在线程被换进换出时混在了一起。这种交换是由线程调度器自动控制的。 * 如果在你的机器上有多个处理器，线程调度器将会在这些处理器之间默默地分发线程。 * * 当main()创建Thread对象时，它并没有捕获任何对这些对象的引用。在使用普通对象时， * 这对于垃圾回收来说是一场公平的游戏，但是在使用Thread时，情况就不同了。 * 每一个Thread都“注册”了它自己，因此确实有一个对它的引用，而且在它的任务退出其run()并死亡之前， * 垃圾回收无法清除它。你可以从输出中看到，这些任务确实运行到了结束， * 因此一个线程会创建一个单独的执行线程，在对start()的调用完成之后，它仍旧会继续存在。 * * @create @author Henry @date 2016-11-16 * 结果可能如下： * Waiting for LiftOff * #1(9), #3(9), #0(9), #3(8), #2(9), #3(7), #1(8), #0(8), #2(8), * #0(7), * #4(9), #2(7), #0(6), #2(6), #3(6), #1(7), #4(8), #3(5), #1(6), * #4(7), * #0(5), #2(5), #3(4), #0(4), #1(5), #2(4), #4(6), #0(3), #2(3), * #3(3), * #4(5), #1(4), #0(2), #2(2), #4(4), #0(1), #3(2), #2(1), #1(3), * #4(3), * #0(Liftoff), #2(Liftoff), #3(1), #4(2), #1(2), #3(Liftoff), * #1(1), * #1(Liftoff), #4(1), #4(Liftoff), * @param args */ public static void main3(String[] args) { for (int i = 0; i < 5; i++) { new Thread(new LiftOff()).start(); } System.out.println("Waiting for LiftOff"); } /** * * Java SE5的java.util.concurrent包中的执行器(Executor)将为你管理Thread 对象， * 从而简化了并发编程。Excetor在客户端和任务执行之间提供了一个间接层； * 与客户端直接执行任务不同，这个中介对象将执行任务。Executor允许你管理异步任务的执行， * 而无须显式地管理线程的生命周期。Executor在JavaSE5/6中启动任务的优先方法。 * CachedThreadPool在程序执行过程中通常会创建与所需数量相同的线程， * 然后在回收旧线程时停止创建新线程，因此它是合理的Executor的首选。 * 只有当这种方式会引发问题是，你才需要切换到FixedTreadPool。 * * @create @author Henry @date 2016-11-16 * * 执行可能结果如下： * #4(9), #2(9), #0(9), #4(8), #0(8), #4(7), #0(7), #4(6), #0(6), * #4(5), #0(5), #4(4), #0(4), #4(3), #0(3), #4(2), #1(9), #4(1), * #4(Liftoff), #3(9), #0(2), #3(8), #1(8), #2(8), #0(1), #3(7), * #0(Liftoff), #2(7), #1(7), #3(6), #2(6), #1(6), #3(5), #2(5), * #1(5), #3(4), #2(4), #1(4), #3(3), #2(3), #1(3), #3(2), #3(1), * #2(2), #2(1), #2(Liftoff), #1(2), #3(Liftoff), #1(1), * #1(Liftoff), * @param args */ public static void main4(String[] args) { ExecutorService exec = Executors.newCachedThreadPool(); for (int i = 0; i < 5; i++) exec.execute(new LiftOff()); exec.shutdown(); } /** * * 你可以很容易地将前面实例中的CachedThreadPool替换为不同类型的Executor. * FixedThreadPool使用了有限的线程集来执行所提交的任务； * 有了FixedThreadPool，你就可以一次性预先执行代价高昂的线程分配， * 因而也就可以限制线程的数量了。这可以节省时间，因为你不用为每个任务都固定地付出 * 创建线程的开销。在事件驱动的系统中，需要线程的事件处理器，通过直接从池中获取线程， * 也可以如你所愿地尽快得到服务。你不会滥用可获得的资源，因为FixedThreadPool使用的 * Thread对象的数量是有界的。 * SingleThreadExecutor就是线程数量为1的FixedThreadPool. * * @create @author Henry @date 2016-11-16 * 执行可能结果如下： * #0(9), #3(9), #1(9), #2(9), #4(9), #1(8), #3(8), #1(7), #3(7), * #1(6), #3(6), #1(5), #3(5), #1(4), #3(4), #1(3), #3(3), #1(2), * #3(2), #1(1), #3(1), #4(8), #2(8), #0(8), #1(Liftoff), #2(7), * #4(7), #0(7), #2(6), #3(Liftoff), #0(6), #4(6), #2(5), #0(5), * #0(4), #2(4), #4(5), #0(3), #4(4), #0(2), #2(3), #4(3), #0(1), * #2(2), #4(2), #0(Liftoff), #2(1), #4(1), #2(Liftoff), * #4(Liftoff), * @param args */ public static void main5(String[] args) { ExecutorService exec = Executors.newFixedThreadPool(5); for (int i = 0; i < 5; i++) exec.execute(new LiftOff()); exec.shutdown(); } /** * * 用Future接收返回值： * * @create @author Henry @date 2016-11-16 * 输出结果如下： * result of TaskWithResult 0 * result of TaskWithResult 1 * result of TaskWithResult 2 * result of TaskWithResult 3 * result of TaskWithResult 4 * result of TaskWithResult 5 * result of TaskWithResult 6 * result of TaskWithResult 7 * result of TaskWithResult 8 * result of TaskWithResult 9 * * @param args */ public static void main6(String[] args) { ExecutorService exec = Executors.newCachedThreadPool(); ArrayList<Future<String>> results = new ArrayList<Future<String>>(); for (int i = 0; i < 10; i++) results.add(exec.submit(new TaskWithResult(i))); for (Future<String> fs : results) { try { System.out.println(fs.isDone()); System.out.println(fs.get()); } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (ExecutionException e) { // TODO Auto-generated catch block e.printStackTrace(); } finally { exec.shutdown(); } } } /** * @create @author Henry @date 2016-11-16 * * 运行结果如下： * #0(9), #2(9), #4(9), #1(9), #3(9), #4(8), #2(8), #0(8), #3(8), * #1(8), * #1(7), #0(7), #2(7), #4(7), #3(7), #1(6), #3(6), #0(6), #2(6), * #4(6), * #1(5), #4(5), #3(5), #2(5), #0(5), #3(4), #0(4), #2(4), #4(4), * #1(4), * #2(3), #4(3), #0(3), #3(3), #1(3), #3(2), #2(2), #1(2), #0(2), * #4(2), * #3(1), #4(1), #0(1), #2(1), #1(1), #3(Liftoff), #2(Liftoff), * #1(Liftoff), * #0(Liftoff), #4(Liftoff), * @param args */ public static void main7(String[] args) { ExecutorService exec = Executors.newCachedThreadPool(); for (int i = 0; i < 5; i++) exec.execute(new SleepingTask()); exec.shutdown(); } /** * * 测试线程优先级 * * @create @author Henry @date 2016-11-16 * 运行结果如下： * Thread[pool-1-thread-6,10,main]:5 * Thread[pool-1-thread-3,1,main]:5 * Thread[pool-1-thread-1,1,main]:5 * Thread[pool-1-thread-5,1,main]:5 * Thread[pool-1-thread-6,10,main]:4 * Thread[pool-1-thread-2,1,main]:5 * Thread[pool-1-thread-4,1,main]:5 * Thread[pool-1-thread-6,10,main]:3 * Thread[pool-1-thread-3,1,main]:4 * Thread[pool-1-thread-1,1,main]:4 * Thread[pool-1-thread-5,1,main]:4 * Thread[pool-1-thread-6,10,main]:2 * Thread[pool-1-thread-2,1,main]:4 * Thread[pool-1-thread-4,1,main]:4 * Thread[pool-1-thread-6,10,main]:1 * Thread[pool-1-thread-2,1,main]:3 * Thread[pool-1-thread-4,1,main]:3 * Thread[pool-1-thread-3,1,main]:3 * Thread[pool-1-thread-1,1,main]:3 * Thread[pool-1-thread-5,1,main]:3 * Thread[pool-1-thread-2,1,main]:2 * Thread[pool-1-thread-4,1,main]:2 * Thread[pool-1-thread-3,1,main]:2 * Thread[pool-1-thread-4,1,main]:1 * Thread[pool-1-thread-2,1,main]:1 * Thread[pool-1-thread-1,1,main]:2 * Thread[pool-1-thread-5,1,main]:2 * Thread[pool-1-thread-3,1,main]:1 * Thread[pool-1-thread-1,1,main]:1 * Thread[pool-1-thread-5,1,main]:1 * * @param args */ public static void main8(String[] args) { ExecutorService exec = Executors.newCachedThreadPool(); for (int i = 0; i < 5; i++) exec.execute(new SimplePriorities(Thread.MIN_PRIORITY)); exec.execute(new SimplePriorities(Thread.MAX_PRIORITY)); exec.shutdown(); } /** * 只要有任何非后台线程还在运行，程序就不会终止。 * 比如：main()的就是一个非后台线程 * * @create @author Henry @date 2016-11-16 * 运行结果如下： * All daemons started * Thread[Thread-1,5,main] com.think.no21.SimpleDaemons@e09713 * Thread[Thread-2,5,main] com.think.no21.SimpleDaemons@19b49e6 * Thread[Thread-8,5,main] com.think.no21.SimpleDaemons@47b480 * Thread[Thread-4,5,main] com.think.no21.SimpleDaemons@156ee8e * Thread[Thread-0,5,main] com.think.no21.SimpleDaemons@de6f34 * Thread[Thread-6,5,main] com.think.no21.SimpleDaemons@83cc67 * Thread[Thread-3,5,main] com.think.no21.SimpleDaemons@10d448 * Thread[Thread-5,5,main] com.think.no21.SimpleDaemons@e0e1c6 * Thread[Thread-7,5,main] com.think.no21.SimpleDaemons@6ca1c * Thread[Thread-9,5,main] com.think.no21.SimpleDaemons@1bf216a * Thread[Thread-2,5,main] com.think.no21.SimpleDaemons@19b49e6 * Thread[Thread-8,5,main] com.think.no21.SimpleDaemons@47b480 * Thread[Thread-4,5,main] com.think.no21.SimpleDaemons@156ee8e * Thread[Thread-0,5,main] com.think.no21.SimpleDaemons@de6f34 * Thread[Thread-6,5,main] com.think.no21.SimpleDaemons@83cc67 * * @param args * @throws Exception */ public static void main9(String[] args) throws Exception { for (int i = 0; i < 10; i++) { Thread daemon = new Thread(new SimpleDaemons()); daemon.setDaemon(true); daemon.start(); } System.out.println("All daemons started"); TimeUnit.MILLISECONDS.sleep(175); } /** * 通过编写定制的ThreadFactory可以定制由Executor创建线程属性。 * * @create @author Henry @date 2016-11-16 * 运行结果如下： * All daemons started * Thread[Thread-1,5,main] com.think.no21.DaemonFromFactory@109a4c * Thread[Thread-3,5,main] com.think.no21.DaemonFromFactory@201f9 * Thread[Thread-5,5,main] com.think.no21.DaemonFromFactory@1cf8583 * Thread[Thread-2,5,main] com.think.no21.DaemonFromFactory@14693c7 * Thread[Thread-4,5,main] com.think.no21.DaemonFromFactory@901887 * Thread[Thread-6,5,main] com.think.no21.DaemonFromFactory@665753 * Thread[Thread-8,5,main] com.think.no21.DaemonFromFactory@ef22f8 * Thread[Thread-9,5,main] com.think.no21.DaemonFromFactory@4a65e0 * Thread[Thread-7,5,main] com.think.no21.DaemonFromFactory@3a6727 * Thread[Thread-0,5,main] com.think.no21.DaemonFromFactory@1e0cf70 * Thread[Thread-1,5,main] com.think.no21.DaemonFromFactory@109a4c * Thread[Thread-3,5,main] com.think.no21.DaemonFromFactory@201f9 * Thread[Thread-5,5,main] com.think.no21.DaemonFromFactory@1cf8583 * Thread[Thread-7,5,main] com.think.no21.DaemonFromFactory@3a6727 * Thread[Thread-9,5,main] com.think.no21.DaemonFromFactory@4a65e0 * Thread[Thread-0,5,main] com.think.no21.DaemonFromFactory@1e0cf70 * Thread[Thread-6,5,main] com.think.no21.DaemonFromFactory@665753 * Thread[Thread-4,5,main] com.think.no21.DaemonFromFactory@901887 * Thread[Thread-2,5,main] com.think.no21.DaemonFromFactory@14693c7 * Thread[Thread-8,5,main] com.think.no21.DaemonFromFactory@ef22f8 * Thread[Thread-9,5,main] com.think.no21.DaemonFromFactory@4a65e0 * Thread[Thread-7,5,main] com.think.no21.DaemonFromFactory@3a6727 * Thread[Thread-8,5,main] com.think.no21.DaemonFromFactory@ef22f8 * Thread[Thread-2,5,main] com.think.no21.DaemonFromFactory@14693c7 * Thread[Thread-0,5,main] com.think.no21.DaemonFromFactory@1e0cf70 * Thread[Thread-6,5,main] com.think.no21.DaemonFromFactory@665753 * Thread[Thread-4,5,main] com.think.no21.DaemonFromFactory@901887 * Thread[Thread-5,5,main] com.think.no21.DaemonFromFactory@1cf8583 * Thread[Thread-3,5,main] com.think.no21.DaemonFromFactory@201f9 * Thread[Thread-1,5,main] com.think.no21.DaemonFromFactory@109a4c * Thread[Thread-9,5,main] com.think.no21.DaemonFromFactory@4a65e0 * Thread[Thread-7,5,main] com.think.no21.DaemonFromFactory@3a6727 * Thread[Thread-5,5,main] com.think.no21.DaemonFromFactory@1cf8583 * Thread[Thread-8,5,main] com.think.no21.DaemonFromFactory@ef22f8 * Thread[Thread-2,5,main] com.think.no21.DaemonFromFactory@14693c7 * Thread[Thread-0,5,main] com.think.no21.DaemonFromFactory@1e0cf70 * Thread[Thread-6,5,main] com.think.no21.DaemonFromFactory@665753 * Thread[Thread-4,5,main] com.think.no21.DaemonFromFactory@901887 * Thread[Thread-3,5,main] com.think.no21.DaemonFromFactory@201f9 * Thread[Thread-1,5,main] com.think.no21.DaemonFromFactory@109a4c * Thread[Thread-5,5,main] com.think.no21.DaemonFromFactory@1cf8583 * Thread[Thread-7,5,main] com.think.no21.DaemonFromFactory@3a6727 * Thread[Thread-9,5,main] com.think.no21.DaemonFromFactory@4a65e0 * Thread[Thread-3,5,main] com.think.no21.DaemonFromFactory@201f9 * Thread[Thread-1,5,main] com.think.no21.DaemonFromFactory@109a4c * Thread[Thread-0,5,main] com.think.no21.DaemonFromFactory@1e0cf70 * Thread[Thread-2,5,main] com.think.no21.DaemonFromFactory@14693c7 * Thread[Thread-8,5,main] com.think.no21.DaemonFromFactory@ef22f8 * Thread[Thread-4,5,main] com.think.no21.DaemonFromFactory@901887 * Thread[Thread-6,5,main] com.think.no21.DaemonFromFactory@665753 * * @param args * @throws Exception */ public static void main(String[] args) throws Exception { ExecutorService exec = Executors.newCachedThreadPool(new DaemonThreadFactory()); for (int i = 0; i < 10; i++) exec.execute(new DaemonFromFactory()); System.out.println("All daemons started"); TimeUnit.MILLISECONDS.sleep(500); } } /** * * 简单的对象实现Runnable接口 * * @create @author Henry @date 2016-11-16 */ class LiftOff implements Runnable { protected int countDown = 10; private static int taskCount = 0; private final int id = taskCount++; public LiftOff() { } public LiftOff(int countDown) { this.countDown = countDown; } public String status() { return "#" + id + "(" + (countDown > 0 ? countDown : "Liftoff") + "), "; } @Override public void run() { while (countDown-- > 0) { System.out.print(status()); /** * Thread.yield()的调用是对线程调度器(java线程机制的一部分，可以将CPU从一个线程转移给另一个线程)的一种建议， * 它在声明：“我已经执行完生命周期中最重要的部分了，此刻正是切换给其他任务执行一段时间的大好时机。” * 这完全是选择性的，但是这里使用它是因为它会在这些示例中产生更加有趣的输出：你更有可能会看到任务换进换出的证据。 * */ Thread.yield(); } } } /** * * 声明带返回值的线程类。 * * @create @author Henry @date 2016-11-16 */ class TaskWithResult implements Callable<String> { private int id; public TaskWithResult(int id) { this.id = id; } @Override public String call() throws Exception { return "result of TaskWithResult " + id; } } /** * * 影响人物行为的一种简单方法是调用sleep(),这将使任务中止执行给定的时间。 * 在LiftOff类中，要是把对yield()的调用换成是调用sleep() * * @create @author Henry @date 2016-11-16 */ class SleepingTask extends LiftOff { @Override public void run() { try { while (countDown-- > 0) { System.out.print(status()); // Old-style; // Thread.sleep(100); // java SE5/6-style; TimeUnit.MILLISECONDS.sleep(100); } } catch (InterruptedException e) { System.err.println("Interrupted"); } } } /** * * 测试线程的优先级的类 * * @create @author Henry @date 2016-11-16 */ class SimplePriorities implements Runnable { private int countDown = 5; private volatile double d;// No optimization private int priority; public SimplePriorities(int priority) { this.priority = priority; } @Override public String toString() { return Thread.currentThread() + ":" + countDown; } @Override public void run() { Thread.currentThread().setPriority(priority); while (true) { // An expensive,interruptable operation: for (int i = 1; i < 100000; i++) { d += (Math.PI + Math.E) / (double) i; if (i % 1000 == 0) Thread.yield(); } System.out.println(this); if (--countDown == 0) return; } } } /** * 后台线程，是指在程序运行的时候再后台提供的一种服务的线程，并且 * 这种线程不属于程序中不可或缺的部分。因此，当所有的非后台线程结束时， * 程序也就终止了，同时会杀死进程中的所有后台线程。 * * @create @author Henry @date 2016-11-16 * */ class SimpleDaemons implements Runnable { @Override public void run() { try { while (true) { TimeUnit.MILLISECONDS.sleep(100); System.out.println(Thread.currentThread() + " " + this); } } catch (InterruptedException e) { System.out.println("sleep() interrupted"); } } } /** * 创建ThreadFactory,将后台状态全部设置为true * * @create @author Henry @date 2016-11-16 * */ class DaemonThreadFactory implements ThreadFactory { @Override public Thread newThread(Runnable r) { Thread t = new Thread(r); t.setDaemon(true); return t; } } /** * 创建一个新的DeamonFromFactory * * @create @author Henry @date 2016-11-16 * */ class DaemonFromFactory implements Runnable { @Override public void run() { try { while (true) { TimeUnit.MILLISECONDS.sleep(100); System.out.println(Thread.currentThread() + " " + this); } } catch (InterruptedException e) { System.out.println("interrupted"); } } } /** * 每个静态的ExecutorService创建方法都被重载为接受一个ThreadFactory对象， * 而这个对象将被用来创建新的线程： * @create @author Henry @date 2016-11-16 * */ class DaemonThreadPoolExecutor extends ThreadPoolExecutor { public DaemonThreadPoolExecutor() { super(0, Integer.MAX_VALUE, 60L, TimeUnit.SECONDS, new SynchronousQueue<Runnable>(),new DaemonThreadFactory()); } }

import java.util.concurrent.TimeUnit; /** * 如果是一个后台线程，那么它创建的任何线程江北自动设置成后台线程， * 例子如下。 * @create @author Henry @date 2016-11-18 * */ public class Daemons { /** * 运行结果如下： * d.isDaemon = true. * DaemonSpawn 0 started. * DaemonSpawn 1 started. * DaemonSpawn 2 started. * DaemonSpawn 3 started. * DaemonSpawn 4 started. * DaemonSpawn 5 started. * DaemonSpawn 6 started. * DaemonSpawn 7 started. * DaemonSpawn 8 started. * DaemonSpawn 9 started. * t[0].isDaemon()=true * t[1].isDaemon()=true * t[2].isDaemon()=true * t[3].isDaemon()=true * t[4].isDaemon()=true * t[5].isDaemon()=true * t[6].isDaemon()=true * t[7].isDaemon()=true * t[8].isDaemon()=true * t[9].isDaemon()=true * * @param args * @throws InterruptedException */ public static void main(String[] args) throws InterruptedException { Thread d =new Thread(new Daemon()); d.setDaemon(true); d.start(); System.out.println("d.isDaemon = "+d.isDaemon()+"."); TimeUnit.SECONDS.sleep(1); } } /** * 在主线程下创建的线程中包含此子线程。 * @create @author Henry @date 2016-11-18 * */ class Daemon implements Runnable { private Thread[] t = new Thread[10]; @Override public void run() { for (int i = 0; i < t.length; i++) { t[i] = new Thread(new DaemonSpawn()); t[i].start(); System.out.println("DaemonSpawn " + i + " started."); } for (int i = 0; i < t.length; i++) System.out.println("t[" + i + "].isDaemon()=" + t[i].isDaemon()); while (true) Thread.yield(); } } /** * * 在子线程内再创建的子线程。 * @create @author Henry @date 2016-11-18 */ class DaemonSpawn implements Runnable { @Override public void run() { while (true) { Thread.yield(); } } } import java.util.concurrent.ExecutorService; import java.util.concurrent.Executors; import java.util.concurrent.TimeUnit; /** * 你应该意识到后台进程在不执行finally子句的情况下就会终止其run()方法. * 此例子说明，当其中一个后台线程结束的时候，其他的后台线程是不能终止的。 * @create @author Henry @date 2016-11-18 * */ class ADeamon implements Runnable { private static int taskCount = 0; private final int id = taskCount++; @Override public void run() { try { System.out.println(id+" Starting ADaemon"); if(id!=1){ TimeUnit.SECONDS.sleep(3); } } catch (InterruptedException e) { System.out.println("Exiting via InterruptedExecption"); }finally{ System.out.println(id+" This should always run?"); } } } /** * 当你运行这个程序时，你将看到finally子句就不会执行， * 但是如果你注释掉对setDaemon()的调用，就会看到finally子句将会执行。 * * @create @author Henry @date 2016-11-18 * */ public class DaemonsDontRunFinally { /** * * @create @author Henry @date 2016-11-18 * 运行结果如下： * Starting ADaemon * @param args * @throws Exception */ public static void main(String[] args) throws Exception { // for (int i = 0; i < 3; i++) { // Thread t=new Thread(new ADeamon()); // t.setDaemon(true); // t.start(); // } ExecutorService exec=Executors.newCachedThreadPool(); for (int i = 0; i < 3; i++) exec.execute(new ADeamon()); TimeUnit.SECONDS.sleep(2); exec.shutdown(); TimeUnit.SECONDS.sleep(10); System.out.println("hello"); } }

转载请注明原文地址: https://ju.6miu.com/read-678020.html

专利

最新回复(0)

java 线程 简单例子

专利

java 线程简单例子