java多线程交替打印abc

你可以使用 `synchronized` 和 `wait` / `notify` 来实现多线程交替打印abc。

以下是一个示例代码：

public class PrintABC {
    private int state;

    public synchronized void printA() throws InterruptedException {
        while (state % 3 != 0) {
            wait();
        }
        System.out.print("A");
        state++;
        notifyAll();
    }

    public synchronized void printB() throws InterruptedException {
        while (state % 3 != 1) {
            wait();
        }
        System.out.print("B");
        state++;
        notifyAll();
    }

    public synchronized void printC() throws InterruptedException {
        while (state % 3 != 2) {
            wait();
        }
        System.out.print("C");
        state++;
        notifyAll();
    }
}

public class Test {
    public static void main(String[] args) {
        PrintABC printABC = new PrintABC();
        new Thread(() -> {
            for (int i = 0; i < 10; i++) {
                try {
                    printABC.printA();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }).start();
        new Thread(() -> {
            for (int i = 0; i < 10; i++) {
                try {
                    printABC.printB();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }).start();
        new Thread(() -> {
            for (int i = 0; i < 10; i++) {
                try {
                    printABC.printC();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }).start();
    }
}

上面的代码创建了三个线程，分别调用 `printA`、`printB` 和 `printC` 方法，来实现多线程交替打印abc的功能。