class Letter implements Runnable {

@Override

public void run() {

//定义循环，循环输出26个字母

for (char ch = 'a'; ch <= 'z'; ch++) {

System.out.print(ch);

try {

//每运行一次休眠时间1000毫秒

Thread.sleep(1000);

} catch (InterruptedException e) {

e.printStackTrace();

}

}

}

}

public class RunnableSleep {

public static void main(String[] args) {

//实例化线程对象

Letter le = new Letter();

Thread t = new Thread(le);

//运行线程 Letter

t.start();

}

}