在Java中的进程之间实现等待？

Thread threadA = new Thread(new Runnable() {
    @Override
    public void run() {
        // 线程A的任务
    }
});

Thread threadB = new Thread(new Runnable() {
    @Override
    public void run() {
        try {
            threadA.join(); // 等待线程A执行完毕
            // 线程B的任务
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }
});

threadA.start();
threadB.start();

public class WaitNotifyExample {
    private boolean conditionMet = false;

    public synchronized void waitForCondition() {
        while (!conditionMet) {
            try {
                wait(); // 当条件不满足时，等待
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
        // 条件满足时执行的任务
    }

    public synchronized void setConditionMet() {
        conditionMet = true;
        notifyAll(); // 唤醒所有等待的线程
    }
}