A、B兩個線程交替打印1 -- 100

方案一：
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

/**
 * created by cjy
 * desc: lock and condition
 */
public class Test100_01 {

    private static Lock lock = new ReentrantLock();
    private static Condition condition1 = lock.newCondition();
    private static Condition condition2 = lock.newCondition();

    public static void main(String[] args) {

        // thread 1
        Thread t1 = new Thread(() -> {
            for (int i = 1; i <= 999; i += 2) {
                lock.lock();
                try {
                    System.out.println("current:" + i);
                    condition1.await();
                    condition2.signal();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
                lock.unlock();
            }
        });

        // thread 2
        Thread t2 = new Thread(() -> {
            for (int i = 2; i <= 1000; i += 2) {
                lock.lock();
                try {
                    System.out.println("current:" + i);
                    condition1.signal();
                    condition2.await();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
                lock.unlock();

            }
        });

        t1.setPriority(Thread.MAX_PRIORITY);
        t1.start();
        t2.start();
    }
}

方案二：

/** * created by cjy * desc: synchronized wait notify */public class Test100_02 {    private static Object object = new Object();    private static boolean isFlag = false;    public static void main(String[] args) {        Thread t1 = new Thread(() -> {            for (int i = 1; i <= 999; i+=2) {                synchronized (object) {                    if (!isFlag) {                        System.out.println("current:" + i);                        isFlag = true;                        try {                            object.wait();                        } catch (InterruptedException e) {                            e.printStackTrace();                        }                        object.notify();                    }                }            }        });        Thread t2 = new Thread(() -> {            for (int i = 2; i <= 1000; i+=2) {                synchronized (object) {                    if (isFlag) {                        isFlag = false;                        System.out.println("current:" + i);                        object.notify();                        try {                            object.wait();                        } catch (InterruptedException e) {                            e.printStackTrace();                        }                    }                }            }        });        t1.setPriority(Thread.MAX_PRIORITY);        t1.start();        t2.start();    }}