多线程-API

1、线程常用API

如何获取线程名称

​ public final String getName():获取线程的名称。

如何给线程设置名称

​ public final void setName(String name):设置线程的名称

针对不是Thread类的子类中如何获取线程对象名称呢?

​ public static Thread currentThread():返回当前正在执行的线程对象

​ Thread.currentThread().getName()

将该线程标记为守护线程或用户线程

当正在运行的线程都是守护线程时，Java 虚拟机退出。

该方法必须在启动线程前调用

class ThreadDaemon extends Thread {
	@Override
	public void run() {
		for (int x = 0; x < 100; x++) {
			System.out.println(getName() + ":" + x);
		}
	}
}

public static void main(String[] args) {
		ThreadDaemon td1 = new ThreadDaemon();
		ThreadDaemon td2 = new ThreadDaemon();

		td1.setName("关羽");
		td2.setName("张飞");

		// 设置收获线程
		td1.setDaemon(true);
		td2.setDaemon(true);

		td1.start();
		td2.start();

		Thread.currentThread().setName("刘备");
		for (int x = 0; x < 5; x++) {
			System.out.println(Thread.currentThread().getName() + ":" + x);
		}
	}

等待该线程终止

public final void join()

public class ThreadJoin extends Thread {
	@Override
	public void run() {
		for (int x = 0; x < 100; x++) {
			System.out.println(getName() + ":" + x);
		}
	}
}

public static void main(String[] args) {
    ThreadJoin tj1 = new ThreadJoin();
    ThreadJoin tj2 = new ThreadJoin();
    ThreadJoin tj3 = new ThreadJoin();

    tj1.setName("李渊");
    tj2.setName("李世民");
    tj3.setName("李元霸");

    tj1.start();
    try {
    tj1.join();
    } catch (InterruptedException e) {
    e.printStackTrace();
    }

    tj2.start();
    tj3.start();
}

如何获取线程对象的优先级?

​ public final int getPriority():返回线程对象的优先级

如何设置线程对象的优先级呢?

​ public final void setPriority(int newPriority)：更改线程的优先级。

注意：

​ 线程默认优先级是5

​ 线程优先级的范围是：1-10。

​ 线程优先级高仅仅表示线程获取的 CPU时间片的几率高，但是要在次数比较多，或者 多次运行的时候才能看到比较好的效果。

	public static void main(String[] args) {
		ThreadPriority tp1 = new ThreadPriority();
		ThreadPriority tp2 = new ThreadPriority();
		ThreadPriority tp3 = new ThreadPriority();

		tp1.setName("东方不败");
		tp2.setName("岳不群");
		tp3.setName("林平之");

		// 获取默认优先级
		// System.out.println(tp1.getPriority());
		// System.out.println(tp2.getPriority());
		// System.out.println(tp3.getPriority());

		// 设置线程优先级
		// tp1.setPriority(100000);
		
		//设置正确的线程优先级
		tp1.setPriority(10);
		tp2.setPriority(1);

		tp1.start();
		tp2.start();
		tp3.start();
	}

线程休眠

​ public static void sleep(long millis)

class ThreadSleepDemo {
	public static void main(String[] args) {
		ThreadSleep ts1 = new ThreadSleep();
		ThreadSleep ts2 = new ThreadSleep();
		ThreadSleep ts3 = new ThreadSleep();

		ts1.setName("林青霞");
		ts2.setName("林志玲");
		ts3.setName("林志颖");

		ts1.start();
		ts2.start();
		ts3.start();
	}
}

class ThreadSleep extends Thread {
	@Override
	public void run() {
		for (int x = 0; x < 100; x++) {
			System.out.println(getName() + ":" + x + ",日期：" + new Date());
			// 睡眠
			// 困了，我稍微休息1秒钟
			try {
				Thread.sleep(1000);
			} catch (InterruptedException e) {
				e.printStackTrace();
			}
		}
	}
}

礼让线程

public static void yield():暂停当前正在执行的线程对象，并执行其他线程。

class ThreadYield extends Thread {
	@Override
	public void run() {
		for (int x = 0; x < 100; x++) {
			System.out.println(getName() + ":" + x);
			Thread.yield();
		}
	}
}

class ThreadYieldDemo {
	public static void main(String[] args) {
		ThreadYield ty1 = new ThreadYield();
		ThreadYield ty2 = new ThreadYield();

		ty1.setName("林青霞");
		ty2.setName("刘意");

		ty1.start();
		ty2.start();
	}
}