threaddemo.java

java应用举例4

public class ThreadDemo extends Thread {
	public void run() {
		for (int i = 0; i < 5; ++i) 
			compute();
	}

	public static void main(String[] args) {
		ThreadDemo thread1 = new ThreadDemo();
		
		Thread thread2 = new Thread(new Runnable() {
			public void run() {
				for (int i = 0; i < 5; ++i) compute();
			}
		});

		if (args.length >= 1)
			thread1.setPriority(Integer.parseInt(args[0]));
		if (args.length >= 2)
			thread2.setPriority(Integer.parseInt(args[1]));

		thread1.start();
		thread2.start();
		
		for (int i = 0; i < 5; ++i) 
			compute();
		
	}

	static ThreadLocal numcalls = new ThreadLocal();

	static synchronized void compute() {
		Integer n = (Integer)numcalls.get();
		
		if (n == null)
			n = new Integer(1);
		else 
			n = new Integer(n.intValue()+1);
		numcalls.set(n);
		
		System.out.println(Thread.currentThread().getName()+": "+n);
		
		for (int i = 0, j = 0; i < 1000000; ++i)
			j += i;
		
		try {
			Thread.sleep((int)(Math.random()*100+1));
		}
		catch(InterruptedException e) {}

		Thread.yield();
	}
}