多线程打印：两个线程打印AB，三个线程打印ABC

package club.interview.algorithm.print;

import io.netty.util.concurrent.DefaultThreadFactory;

import java.util.concurrent.*;

/**
 * 多线程打印
 * -- 2个线程交替打印 AB 换行
 * -- 3个线程交替打印 ABC 换行
 * -- 2/3个线程交替打印 HHO 换行
 * - 统一思路
 * -- 统一任务类 ，寻找执行线程，设定打印内容
 * <p>
 * code
 * -- 用线程池 (规范)
 * -- 定义外部成员变量用final (专业)
 *
 * -- 思路来自 多线程打印 从 0 - 100
 * {@link Zero2Hundred}
 * @author QuCheng on 2020/9/9.
 */
public class ABC {

    /**
     * 自己定义打印内容,想打啥打啥
     */
    private final char[] threads = new char[]{‘A‘, ‘B‘, ‘C‘, ‘D‘};
    /**
     * 打印次数
     */
    private final int times = 10;

    /**
     * 总计操作次数
     */
    private final int size = times * threads.length;
    /**
     * 开始
     */
    private int count = 0;

    private void waitNotifyCount() {
        ExecutorService es = new ThreadPoolExecutor(threads.length, threads.length, 0, TimeUnit.MILLISECONDS,
                new SynchronousQueue<>(), new DefaultThreadFactory("Qc"));
        for (int i = 0; i < threads.length; i++) {
            es.execute(new Task(i));
        }
        es.shutdown();
    }


    class Task implements Runnable {
        private final int id;

        public Task(int id) {
            this.id = id;
        }

        @Override
        public void run() {
            while (true) {
                synchronized (Task.class) {
                    if (count >= size) {
                        break;
                    }
                    // 寻找对应的执行线程
                    if (count % threads.length == id) {
                        // 设置执行的内容
                        if (id < (threads.length - 1)) {
                            System.out.print(threads[id]);
                        } else {
                            System.out.println(threads[id]);
                        }
                        count++;
                        Task.class.notifyAll();
                    } else {
                        try {
                            Task.class.wait();
                        } catch (InterruptedException e) {
                            e.printStackTrace();
                        }
                    }
                }
            }
        }
    }

    public static void main(String[] args) {
        ABC abc = new ABC();
        abc.waitNotifyCount();
    }
}