Thread 类的基本用法

线程创建

优先选择 lambda 表达式

Thread thread = new Thread(() -> {});

线程中断

thread.interrupt();

public static void main(String[] args) {Thread thread = new Thread(() -> {while (!Thread.currentThread().isInterrupted()) {//Thread.currentThread(); -> 获取当前线程引用System.out.println("Hello Thread");try {Thread.sleep(10000);//若阻塞时间过长,即便输入0后也不会立即终止。//必须得等阻塞完之后才会终止执行} catch (InterruptedException e) {// throw new RuntimeException(e);// e.printStackTrace();//不会停止进程  sleep 会清除标志位break;}}});thread.start();Scanner scanner = new Scanner(System.in);System.out.println("按零退出线程");int input = scanner.nextInt();if (input == 0) {thread.interrupt();}}

线程等待

thread.join();

public class Demo10 {private static int ret = 0;public static void main(String[] args) {Thread thread = new Thread(() -> {for (int i = 1; i <= 1000; i++) {ret += i;}});thread.start();System.out.println(ret);}
}

此时输出的结果就为 0。因为 thread 线程和 main 线程同时进行导致 main 线程在读取 ret 的值时仍旧为 0 。

解决方法：只需在线程 thread start 之后调用 thread 的 join 方法，此时 main 线程就会排在 thread 线程之后。此时的输出结果即为正常结果。

public class Demo10 {private static int ret = 0;public static void main(String[] args) throws InterruptedException {Thread thread = new Thread(() -> {for (int i = 1; i <= 1000; i++) {ret += i;}});thread.start();thread.join();System.out.println(ret);}
}

线程休眠

Thread.sleep(1000);

获取线程实例

    public static void main(String[] args) {Thread t1 = new Thread() {public void run() {//可通过this.getName()获取当前线程名System.out.println(this.getName());}};t1.start();Thread t2 = new Thread(new Runnable() {public void run() {//System.out.println(this.getName());//报错,此时的 this 指代的是 Runnable, 而 Runnable 内没有 getName() 方法//仍需调用用Thread类中的Thread.currentThread()获取当前线程Thread cur = Thread.currentThread();System.out.println(cur.getName());System.out.println(Thread.currentThread().getName());}});t2.start();Thread t3 = new Thread(() -> {//lambda 表达式也是如此,同t2,不支持thisSystem.out.println(Thread.currentThread().getName());});t3.start();}