Java多线程编程7--实例--顺序打印3次ABC

    正常的情况下，线程在运行时多个线程之间执行任务的时机是无序的。可以通过改造代码的方式使它们运行具有有序性。

public class MyThread extends Thread {
    private Object lock;
    private String showChar;
    private int showNumPosition;
    private int printCount = 0; //统计打印了几个字母

    private volatile static int addNumber = 1;

    public MyThread(Object lock, String showChar, int showNumPosition) {
        super();
        this.lock = lock;
        this.showChar = showChar;
        this.showNumPosition = showNumPosition;
    }

    @Override
    public void run() {
        try {
            synchronized (lock) {
                while (true) {
                    if (addNumber % 3 == showNumPosition) {
                        System.out.println("ThreadName="
                                + Thread.currentThread().getName()
                                + ",runCount=" + addNumber + " " + showChar);
                        lock.notifyAll();
                        addNumber++;
                        printCount++;
                        if (printCount == 3) {
                            break;
                        }
                    } else {
                        lock.wait();
                    }
                }
            }
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }
}

public class Run {
    public static void main(String[] args) throws InterruptedException {
        Object lock = new Object();
        MyThread a = new MyThread(lock, "AA", 1);
        MyThread b = new MyThread(lock, "BB", 2);
        MyThread c = new MyThread(lock, "CC", 0);
        a.start();
        b.start();
        c.start();
    }
}

ThreadName=Thread-0,runCount=1 AA ThreadName=Thread-1,runCount=2 BB ThreadName=Thread-2,runCount=3 CC ThreadName=Thread-0,runCount=4 AA ThreadName=Thread-1,runCount=5 BB ThreadName=Thread-2,runCount=6 CC ThreadName=Thread-0,runCount=7 AA ThreadName=Thread-1,runCount=8 BB ThreadName=Thread-2,runCount=9 CC