两个线程交替打印数字和字母

public class LockSupportTest {
    static Thread t1 = null;
    static Thread t2 = null;

    public static void main(String[] args) {
        char[] a1 = "1234567".toCharArray();
        char[] a2 = "ABCDEFG".toCharArray();

        t1 = new Thread(() -> {
            for (char c : a1) {
                System.out.println(c);
                // 叫醒t2
                LockSupport.unpark(t2);
                // t1阻塞，当前线程阻塞
                LockSupport.park();
            }
        });

        t2 = new Thread(() -> {
            for (char c : a2) {
                // t2阻塞
                LockSupport.park();
                System.out.println(c);
                // 叫醒t1
                LockSupport.unpark(t1);


            }
        });
        t1.start();
        t2.start();
    }
}

public class WaitNotifyTest {

    public static void main(String[] args) {
        final Object o = new Object();

        char[] a1 = "1234567".toCharArray();
        char[] a2 = "ABCDEFG".toCharArray();

        new Thread(() -> {
            synchronized (o) {
                for (char c : a1) {
                    System.out.println(c);
                    try {
                        o.notify();
                        // 让出锁
                        o.wait();
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }
                // 必须唤醒，不然程序无法终止
                o.notify();
            }
        }, "t1").start();

        new Thread(() -> {
            synchronized (o) {
                for (char c : a2) {
                    System.out.println(c);
                    try {
                        o.notify();
                        // 让出锁
                        o.wait();
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }
                // 必须唤醒，不然程序无法终止
                o.notify();
            }
        }, "t2").start();
    }
}

1
A
2
B
3
C
4
D
5
E
6
F
7
G

Process finished with exit code 0