今天去面試遇見這道題，當(dāng)時(shí)覺得挺簡(jiǎn)單的，結(jié)果寫起來(lái)一緊張卡殼了，回來(lái)想了一下，思路挺明確的，同一個(gè)類，兩個(gè)線程訪問它，一個(gè)打完之后將另一個(gè)喚醒就好了。
代碼如下：

package com.cwj.thread;

/**
 * Created by cwj on 18-12-7.
 */
public class Print_letter implements Runnable{
    char ch = 97;

    @Override
    public void run() {
        while (true){
            synchronized (this){
                notify();
                try {
                    Thread.currentThread().sleep(1000);
                }catch (InterruptedException e){
                    e.printStackTrace();
                }

                if (ch < 123){
                    System.out.println(Thread.currentThread().getName() + " " + ch);
                    ch++;
                    try {
                        wait();
                    }catch (InterruptedException e){
                        e.printStackTrace();
                    }
                }
            }
        }
    }

    public static void main(String[] args) {
        Print_letter t = new Print_letter();
        Thread t1 = new Thread(t);
        Thread t2 = new Thread(t);
        t1.start();
        t2.start();
    }
}