计算消逝时间

Question

该程序将向用户显示程序的开始时间，结束时间和流逝时间。例如，如果程序在09:23:45开始并在09:23:55结束，则对用户的输出将如此，开始时间：09h：23m：45s结束时间：09h：23m：55s经过时间00h ：00米：10秒。我有问题，会显示时间... 请帮助

这是主要的

import java.util.concurrent.TimeUnit; 
import java.text.SimpleDateFormat; 
public class ElapsedTimeWatch { 

public static void main(String... args) throws InterruptedException { 

    TimeWatch watch = TimeWatch.start(); 
    SimpleDateFormat dateFormat = new SimpleDateFormat("HH'h':mm'm':ss's'"); 
    System.out.println("Start Time is : " + dateFormat.format(timestart)); 
    String.format("%02dh:%02dm:%02ds", 
        TimeUnit.MILLISECONDS.toHours(watch.timestart()),//dateFormat.format(start) 
        TimeUnit.MILLISECONDS.toSeconds(watch.timestart()) - 
          TimeUnit.MINUTES.toSeconds(TimeUnit.MILLISECONDS.toMinutes(watch.timestart()))); 









    Thread.sleep(1000 * 10); 



    System.out.println("End Time is : " + dateFormat.format(timeend)); 
    String.format("%02dh:%02dm:%02ds", 
        TimeUnit.MILLISECONDS.toHours(watch.timeend()), 
        TimeUnit.MILLISECONDS.toSeconds(watch.timeend()) - 
          TimeUnit.MINUTES.toSeconds(TimeUnit.MILLISECONDS.toMinutes(watch.timeend()))); 









    System.out.println("Elapsed Time custom format: " + watch.toMinuteSeconds()); 



} 
} 

时手表类

import java.util.concurrent.TimeUnit; 

public class TimeWatch { 

long starts; 



private TimeWatch() { 
    reset(); 
} 

public static TimeWatch start() { 
    return new TimeWatch(); 
} 

public TimeWatch reset() { 
    starts = System.currentTimeMillis(); 
    return this; 
} 




public long time() { 
    long ends = System.currentTimeMillis(); 
    return ends - starts; 
} 

//Start Time 
public long timestart() { 
    starts = System.currentTimeMillis(); 
    return starts; 
} 
//End Time 
public long timeend() { 
    long ends = System.currentTimeMillis(); 
    return ends; 
} 





public long time(TimeUnit unit) { 
    return unit.convert(time(), TimeUnit.MILLISECONDS); 


public String toMinuteSeconds(){ 
    return String.format("%d min, %d sec", time(TimeUnit.MINUTES), 
      time(TimeUnit.SECONDS) - time(TimeUnit.MINUTES)); 
} 




} 

Answer 1

由于根据oracle documentation，System.nanoTime（）与时钟无关。所以，在这种情况下，我们可以使用System.currentTimeMillis();来启动定时器。一旦计时器停止，我们可以使用下面的代码打印失效：

public static void main(String[] args) throws InterruptedException { 
    long start = System.currentTimeMillis(); 
    SimpleDateFormat dateFormat = new SimpleDateFormat("HH'h':mm'm':ss's'"); 
    Thread.sleep(10000); 
    long end = System.currentTimeMillis(); 
    long difference = end - start; 
    System.out.println("Start :" + dateFormat.format(start)); 
    System.out.println("End :" + dateFormat.format(end)); 
    String format = String.format("%d min, %d sec", 
      TimeUnit.MILLISECONDS.toMinutes(difference), 
      TimeUnit.MILLISECONDS.toSeconds(difference) - 
      TimeUnit.MINUTES.toSeconds(TimeUnit.MILLISECONDS.toMinutes(difference)) 
     ); 
    System.out.println(format); 
}