【多線程】synchronized同步塊

class TextThread implements Runnable{
	
	private int num = 5;

	@Override
	public void run() {

		while(true){
			// 同步代碼塊
			synchronized (this) {  
				if(num > 0){
					try {
						Thread.sleep(1000);
					} catch (InterruptedException e) {
						System.out.println(Thread.currentThread().getName() + "出錯了！");
					}
					System.out.println(Thread.currentThread().getName() + "數字爲：" + num--);
				}else{
					System.out.println(Thread.currentThread().getName() + "退出來！！！");
					break;
				}
			}
		}
		
	}
	
}
public class SynchronizedTest {
	public static void main(String[] args) {
		TextThread t = new TextThread();
		// 啓動2個線程，
		new Thread(t).start();
		new Thread(t).start();		
	}
}