Java 线程的优先级(setPriority)案例详解

public class MyThread1 extends Thread {
	@Override
	public void run() {
		System.out.println("MyThread1 run priority=" + this.getPriority());
		MyThread2 thread2 = new MyThread2();
		thread2.start();
	}
}
 
 
public class MyThread2 extends Thread {
	@Override
	public void run() {
		System.out.println("MyThread2 run priority=" + this.getPriority());
	}
}
 
public static void main(String[] args) {
		System.out.println("main thread begin priority="
				+ Thread.currentThread().getPriority());
		
		Thread.currentThread().setPriority(6);
		
		System.out.println("main thread end   priority="
				+ Thread.currentThread().getPriority());
		
		MyThread1 thread1 = new MyThread1();
		thread1.start();
	}

public class MyThread1 extends Thread {
	@Override
	public void run() {
		long beginTime = System.currentTimeMillis();
		long addResult = 0;
		for (int j = 0; j < 10; j++) {
			for (int i = 0; i < 50000; i++) {
				Random random = new Random();
				random.nextInt();
				addResult = addResult + i;
			}
		}
		long endTime = System.currentTimeMillis();
		System.out.println("★★★★★thread 1 use time=" + (endTime - beginTime));
	}
}
 
public class MyThread2 extends Thread {
	@Override
	public void run() {
		long beginTime = System.currentTimeMillis();
		long addResult = 0;
		for (int j = 0; j < 10; j++) {
			for (int i = 0; i < 50000; i++) {
				Random random = new Random();
				random.nextInt();
				addResult = addResult + i;
			}
		}
		long endTime = System.currentTimeMillis();
		System.out.println("☆☆☆☆☆thread 2 use time=" + (endTime - beginTime));
	}
}
 
public static void main(String[] args) {
		for (int i = 0; i < 5; i++) {
			MyThread1 thread1 = new MyThread1();
			thread1.setPriority(1);
			thread1.start();
 
			MyThread2 thread2 = new MyThread2();
			thread2.setPriority(10);
			thread2.start();
		}
	}

public class MyThread1 extends Thread {
	@Override
	public void run() {
		long beginTime = System.currentTimeMillis();
		for (int i = 0; i < 1000; i++) {
			Random random = new Random();
			random.nextInt();
		}
		long endTime = System.currentTimeMillis();
		System.out.println("★★★★★thread 1 use time=" + (endTime - beginTime));
	}
}
 
public class MyThread2 extends Thread {
	@Override
	public void run() {
		long beginTime = System.currentTimeMillis();
		for (int i = 0; i < 1000; i++) {
			Random random = new Random();
			random.nextInt();
		}
		long endTime = System.currentTimeMillis();
		System.out.println("☆☆☆☆☆thread 2 use time=" + (endTime - beginTime));
	}
}
 
 
public static void main(String[] args) {
		for (int i = 0; i < 5; i++) {
			MyThread1 thread1 = new MyThread1();
			thread1.setPriority(5);
			thread1.start();
 
			MyThread2 thread2 = new MyThread2();
			thread2.setPriority(6);
			thread2.start();
		}
	}

public class MyThread extends Thread {
	private int i = 0;
 
	@Override
	public void run() {
		try {
			while (true) {
				i++;
				System.out.println("i=" + (i));
				Thread.sleep(1000);
			}
		} catch (InterruptedException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
}
 
 
public static void main(String[] args) {
		try {
			MyThread thread = new MyThread();
			thread.setDaemon(true);//设置守护线程
			thread.start();
			Thread.sleep(5000);
			System.out.println("我离开thread对象也不再打印了，也就是停止了！");
		} catch (InterruptedException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}