NotifyTest

NotifyTest.java

public class NotifyTest {
    private final String flag[] = {"true"};

    class NotifyThread extends Thread {
        public NotifyThread(String name) {
            super(name);
        }

        public void run() {
            try {
                Thread.sleep(3000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            synchronized (flag) {
                flag[0] = "false";
                flag.notifyAll();
            }
        }
    }

    class WaitThread extends Thread {
        public WaitThread(String name) {
            super(name);
        }

        public void run() {
            synchronized(flag) {
                while(!flag[0].equals("false")) {
                    System.out.println(getName()+ " starts waiting!");
                    long waitTime = System.currentTimeMillis();
                    try {
                        flag.wait();
                    } catch(InterruptedException e) {
                        e.printStackTrace();
                    }

                    waitTime = System.currentTimeMillis() - waitTime;
                    System.out.println("wait time: " + waitTime);
                }
                System.out.println(getName() + "end waiting!");
            }
        }
    }

    public static void main(String [] args) throws InterruptedException{
        System.out.println("Main thread start run!");
        NotifyTest notifyTest = new NotifyTest();
        NotifyThread notifyThread = notifyTest.new NotifyThread("notify01");
        WaitThread waitThread1 = notifyTest.new WaitThread("wait01");
        WaitThread waitThread2 = notifyTest.new WaitThread("wait02");
        WaitThread waitThread3 = notifyTest.new WaitThread("wait03");
        notifyThread.start();
        waitThread1.start();
        waitThread2.start();
        waitThread3.start();
    }
}