计算两个时间段差值的Java程序

在本文中，让我们探索在Java中找出两个时间段之间差异的各种方法。为简单起见，我们假设提供给我们的时间段的格式为 HH:MM:SS

例子

Input : 1st Time Period :- 18:00:00
    2nd Time Period :- 21:00:00
Output: 3 hours 0 minutes and 0 seconds
 
Input : 1st Time Period :- 17:00:00
        2nd Time Period :- 23:22:00
Output: 6 hours 22 minutes and 0 seconds

方法 1 :- 使用 SimpleDateFormat 类和 Date 类

SimpleDateFormat 类已添加到第 7 版 JDK 中的Java.text 包中。通过创建 SimpleDateFormat 对象以 HH:MM:SS 格式解析时间段。 SimpleDateFormat 对象解析时间段并返回一个 Date 对象，该对象可用于计算经过的时间。

下面是上述方法的代码：

Java

// Java Program to Find the difference
// between Two Time Periods
  
// Importing the Date Class from the util package
import java.util.*;
  
// Importing the SimpleDateFormat
// Class from the text package
import java.text.*;
  
public class GFG {
  
    public static void main(String[] args) throws Exception
    {
  
        // Dates to be parsed
        String time1 = "18:00:00";
        String time2 = "7:30:50";
  
        // Creating a SimpleDateFormat object
        // to parse time in the format HH:MM:SS
        SimpleDateFormat simpleDateFormat
            = new SimpleDateFormat("HH:mm:ss");
  
        // Parsing the Time Period
        Date date1 = simpleDateFormat.parse(time1);
        Date date2 = simpleDateFormat.parse(time2);
  
        // Calculating the difference in milliseconds
        long differenceInMilliSeconds
            = Math.abs(date2.getTime() - date1.getTime());
  
        // Calculating the difference in Hours
        long differenceInHours
            = (differenceInMilliSeconds / (60 * 60 * 1000))
              % 24;
  
        // Calculating the difference in Minutes
        long differenceInMinutes
            = (differenceInMilliSeconds / (60 * 1000)) % 60;
  
        // Calculating the difference in Seconds
        long differenceInSeconds
            = (differenceInMilliSeconds / 1000) % 60;
  
        // Printing the answer
        System.out.println(
            "Difference is " + differenceInHours + " hours "
            + differenceInMinutes + " minutes "
            + differenceInSeconds + " Seconds. ");
    }
}

输出

Difference is 10 hours 29 minutes 10 Seconds. 

时间复杂度： O(1)

方法 2 :- 使用 LocalTime 和 ChronoUnit 类

Java在第 8 个 JDK 版本中带来了大量特性，其中很少有Java.time 包中的 LocalTime 和 ChronoUnit 类。 LocalTime 对象以 HH:MM:SS 格式解析日期，ChronoUnit 用于获取小时、分钟和秒的差异。

下面是上述方法的代码：

Java

// Java program to get the difference
// between Two Time Periods in Java
  
// Importing the LocalTime class
import java.time.*;
  
// Importing the ChronoUnit class
import java.time.temporal.ChronoUnit;
  
class GFG {
    public static void main(String[] args)
    {
  
        // Parsing Time Period in the format HH:MM:SS
        LocalTime time1 = LocalTime.of(18, 00, 00);
        LocalTime time2 = LocalTime.of(21, 22, 00);
  
        // Calculating the difference in Hours
        long hours = ChronoUnit.HOURS.between(time1, time2);
  
        // Calculating the difference in Minutes
        long minutes
            = ChronoUnit.MINUTES.between(time1, time2) % 60;
  
        // Calculating the difference in Seconds
        long seconds
            = ChronoUnit.SECONDS.between(time1, time2) % 60;
  
        // Printing the difference
        System.out.println(
            "Difference is " + hours + " hours " + minutes
            + " minutes " + seconds + " seconds.");
    }
}

输出

Difference is 3 hours 22 minutes 0 seconds.

时间复杂度： O(1)