如何通過Java8的Instant去統計程序執行時間?

代碼如下所示

import java.time.Duration;
import java.time.Instant;
import java.util.concurrent.TimeUnit;

public class DurationDemo {

    public static void main(String[] args) throws InterruptedException {
        //開始時間
        Instant stime = java.time.Instant.now();
        //程序執行過程
        TimeUnit.SECONDS.sleep(2);
        //結束時間
        Instant etime = java.time.Instant.now();
        //統計時間_毫秒
        System.out.println(Duration.between(stime, etime).toMillis());
        //統計時間 _秒
        System.out.println(Duration.between(stime, etime).getSeconds());
        //統計時間_分鍾
        System.out.println(Duration.between(stime, etime).toMinutes());
    }
}