public static native void sleep(long millis) throws InterruptedException;

sleep是本地靜態方法。
sleep的作用是讓執行緒進入TIME_WAITING狀態，引數是多少毫秒。

class Test {
    public static void main(String[] args){
        Thread thread = new Thread(()->{
            try {
                Thread.sleep(2000);
                System.out.println(
 
"over");
            } catch (InterruptedException e) {
                System.out.println("interrupt");
            }
        });
        thread.start();
    }
}

/**
 結果：2秒後看到over
 */

sleep可被interrupt打斷，丟擲InterruptedException。

class Test {
    public static void main(String[] args){
        Thread thread 
 
= new Thread(()->{
            try {
                Thread.sleep(2000);
                System.out.println("over");
            } catch (InterruptedException e) {
                System.out.println("interrupt");
            }
        });
        thread.start();
        thread.interrupt();
    }
}

 
/**
 結果：立刻看到interrupt
 */

注意：sleep方法並不釋放鎖。