*简单卖票

public class SimpleThread extends Thread{

	private static int ticNum = 100;		//static
	public void run(){
		while(true){
			if(ticNum>0){
				System.out.println(Thread.currentThread().getName()+"---:"+ticNum--);
			}else{
				break;
			}
		}
	}
	
	public static void main(String[] args){
	
		SimpleThread thread0 = new SimpleThread();
		SimpleThread thread1 = new SimpleThread();
		SimpleThread thread2 = new SimpleThread();
		SimpleThread thread3 = new SimpleThread();
		
		thread0.start();
		thread1.start();
		thread2.start();
		thread3.start();
		
	}
}

 

public class SimpleThread implements Runnable{		//安全问题

	private int ticNum = 100;			//
	public void run(){
		while(true){
			if(ticNum>0){
				System.out.println(Thread.currentThread().getName()+"---:"+ticNum--);
			}else{
				break;
			}
		}
	}
	
	public static void main(String[] args){
	
		SimpleThread t = new SimpleThread();
	
		Thread thread0 = new Thread(t);
		Thread thread1 = new Thread(t);
		Thread thread2 = new Thread(t);
		Thread thread3 = new Thread(t);
		
		thread0.start();
		thread1.start();
		thread2.start();
		thread3.start();
		
	}
}

 安全问题演示：

public class SimpleThread implements Runnable{

	private int ticNum = 100;
	public void run(){
		while(true){
			if(ticNum>0){
				try{
					Thread.currentThread().sleep(50);
				}catch(InterruptedException e){
					e.printStackTrace();
				}
				System.out.println(Thread.currentThread().getName()+"---:"+ticNum--);
			}else{
				break;
			}
		}
	}
	
	public static void main(String[] args){
	
		SimpleThread t = new SimpleThread();
	
		Thread thread0 = new Thread(t);
		Thread thread1 = new Thread(t);
		Thread thread2 = new Thread(t);
		Thread thread3 = new Thread(t);
		
		thread0.start();
		thread1.start();
		thread2.start();
		thread3.start();
		
	}
}

 

 

synchronized：

public class SimpleThread implements Runnable{

	private int ticNum = 100;
	public void run(){
		while(true){
			synchronized(this){			//
				if(ticNum>0){
					System.out.println(Thread.currentThread().getName()+"---:"+ticNum--);
				}else{
					break;
				}
			}
		}
	}
	
	public static void main(String[] args){
	
		SimpleThread t = new SimpleThread();
	
		Thread thread0 = new Thread(t);
		Thread thread1 = new Thread(t);
		Thread thread2 = new Thread(t);
		Thread thread3 = new Thread(t);
		
		thread0.start();
		thread1.start();
		thread2.start();
		thread3.start();
		
	}
}