java线程同步

这次写一个多线程的demo，用生活中的例子来讲,妈妈要做饭,打开冰箱一看,菜和米都没有了。于是让我去买菜,让爸爸去买米。我去买菜和爸爸去买米是并发执行的,互相不干涉。但是妈妈没有米和菜式没法做饭的,所以等着米和菜把饭做好。代码如下:

public class threadDemo {

    /**
     * @param args
     */
    private static Object lock = new Object();

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Thread t1 = new Thread(new Runnable() {

            @Override
            public void run() {
                synchronized (lock) {
                    System.out.println("妈妈去做饭,发现没有菜和米,让我去买菜,爸爸去买米");
                    try {
                        lock.wait();
                        lock.wait();
                    } catch (InterruptedException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                    System.out.println("妈妈把做饭做好");
                }
            }
        });
        t1.start();
        Thread t2 = new Thread(new Runnable() {

            @Override
            public void run() {
                synchronized (lock) {
                    System.out.println("我去买菜...");
                    try {
                        Thread.sleep(2000);
                    } catch (InterruptedException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                    System.out.println("把菜给妈妈");
                    lock.notify();
                }
            }
        });
        t2.start();
        Thread t3 = new Thread(new Runnable() {

            @Override
            public void run() {
                System.out.println("爸爸去买米...");
                synchronized (lock) {
                    try {
                        Thread.sleep(3000);
                    } catch (InterruptedException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                    System.out.println("把米给妈妈");
                    lock.notify();
                }
            }
        });
        t3.start();
    }
    
}

效果:

妈妈去做饭,发现没有菜和米,让我去买菜,爸爸去买米
我去买菜...
爸爸去买米...
把菜给妈妈
把米给妈妈
妈妈把做饭做好