Thread中一些简单的API

Thread中一些简单的API

/**
 * @program: ThreadDemo
 * @description: Thread中一些简单的API
 * @author: hs96.cn@Gmail.com
 * @create: 2020-08-28
 */
public class ThreadSimpleAPI {
    public static void main(String[] args) {
        Thread t1 = new Thread(() -> {
            Optional.of("Hello").ifPresent(System.out::println);
            try {
                Thread.sleep(1_000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }, "t1");

        t1.start();

        // 线程名称。
        Optional.of(t1.getName()).ifPresent(System.out::println);
        // 线程ID。++threadSeqNumber
        Optional.of(t1.getId()).ifPresent(System.out::println);
        // 线程优先级，默认为5.
        Optional.of(t1.getPriority()).ifPresent(System.out::println);
    }
}

很简单的api运行效果如下：

接下来再通过代码来验证：线程不一定会按照指定的优先级执行。

import java.util.Optional;

/**
 * @program: ThreadDemo
 * @description: 线程优先级：验证：线程不一定会按照指定的优先级执行。
 * @author: hs96.cn@Gmail.com
 * @create: 2020-08-28
 */
public class ThreadSimpleAPI2 {
    public static void main(String[] args) {
        Thread t1 = new Thread(() -> {
            for (int i = 0; i < 1000; i++) {
                Optional.of(Thread.currentThread().getName() + "-Index-" + i).ifPresent(System.out::println);
            }
        }, "t1");
        t1.setPriority(Thread.MAX_PRIORITY);

        Thread t2 = new Thread(() -> {
            for (int i = 0; i < 1000; i++) {
                Optional.of(Thread.currentThread().getName() + "-Index-" + i).ifPresent(System.out::println);
            }
        }, "t2");
        t2.setPriority(Thread.NORM_PRIORITY);

        Thread t3 = new Thread(() -> {
            for (int i = 0; i < 1000; i++) {
                Optional.of(Thread.currentThread().getName() + "-Index-" + i).ifPresent(System.out::println);
            }
        }, "t3");
        t3.setPriority(Thread.MIN_PRIORITY);

        t1.start();
        t2.start();
        t3.start();
    }
}

运行结果如下：

可以看到他们是交替执行的，所以线程的优先级我们应该在逻辑上去实现。这里就做个了解。