极客教程如何在Java中计算两个日期之间的时间差
我们面临的挑战是使用Java语言来确定两个日期之间的差异。
给出两个日期的开始日期以及结束日期，时间以字符串表示。
例1 :
输入以下日期。
开始日期=10/01/2018 01:10:20。
结束日期=10/06/2020 06:30:50。
输出结果。2,152天，5,20,30秒，或5,20小时。
例2 :
输入以下日期。
开始日期和结束日期：10-01-2019和06-06-2020
结果。152天，5小时，0分钟和0秒。
使用Java SimpleDateFormat类
要比较两个日期，请使用SimpleDateFormat和Date类。以下步骤。
- 通过创建SimpleDateFormat类的一个实例，将字符串格式转换为日期对象。
- 要创建一个日期，使用simpleDateFormat类的parse()方法从一个字符串中提取起始日期和结束日期。
- 使用Java方法getTime()作为d2.getTime()-d1.getTime，确定两个日期之间的时间差，以毫秒为单位（）。
- 为了确定两个日期之间的差异，使用日期-时间数学公式。返回两个指定日期之间的年、日、小时、分钟和秒。
- 打印完成的产品。
上述策略的实践情况如下。
文件名：TimeDiff1.java
// Java code for the method described above
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
class TimeDiff1 {
// method for printing the difference between the
// startdate as well as the enddate
static void
findDiff(String startdate,
String enddate)
{
// SimpleDateFormat is used for converting the
// string format into the date instance
SimpleDateFormat sdf1
= new SimpleDateFormat(
"dd-MM-yyyy HH:mm:ss");
// Try Block
try {
// parse method is used for parsing
// the text from a string to
// produce the date
Date d0 = sdf1.parse(startdate);
Date d1 = sdf1.parse(enddate);
// Calculating the time difference
// in milliseconds
long Time_difference
= d0.getTime() - d1.getTime();
// Calculating the time difference in
// terms of seconds, minutes, hours, years,
// and days
long Seconds_difference
= (Time_difference
/ 1000)
% 60;
long Minutes_difference
= (Time_difference
/ (1000 * 60))
% 60;
long Hours_difference
= (Time_difference
/ (1000 * 60 * 60))
% 24;
long Years_difference
= (Time_difference
/ (1000l * 60 * 60 * 24 * 365));
long Days_difference
= (Time_difference
/ (1000 * 60 * 60 * 24))
% 365;
// Printing the difference between the dates in terms of
// years, in days, in hours, in
// seconds, as well as in minutes
System.out.print(
"Difference "
+ "between the two dates is: ");
System.out.println(
Years_difference
+ " years, "
+ Days_difference
+ " days, "
+ Hours_difference
+ " hours, "
+ Minutes_difference
+ " minutes, "
+ Seconds_difference
+ " seconds");
}
// Catching the Exception
catch (ParseException e) {
e.printStackTrace();
}
}
// Main Code
public static void main(String args[])
{
// user Start Date
String startdate
= "11-01-2018 02:11:20";
// user end Date
String enddate
= "11-06-2020 07:31:50";
// Method Call
findDiff(startdate, enddate);
}
}
输出 。
The difference between the two dates is: -2 years, -152 days, -5 hours, -20 minutes, -30 seconds
使用Java TimeUnit类
通过使用Java内置的TimeUnit类，我们可以更准确地确定两个日期之间的差异。上述方法的实际应用如下。
文件名：TimeDiff2.java
// Java program for calculating the
// difference between the two dates
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.concurrent.TimeUnit;
import java.util.Date;
class TimeDiff2 {
// Method for printing the difference between
// startdate as well as enddate
static void findDiff(String startdate,
String enddate)
{
// SimpleDateFormat for converting the
// string format into the date instance
SimpleDateFormat sdf1
= new SimpleDateFormat(
"dd-MM-yyyy HH:mm:ss");
// using the Try block
try {
// parse method is used for parsing
// the text from a string for
// producing the date
Date d0 = sdf1.parse(startdate);
Date d1 = sdf1.parse(enddate);
// Calculating the time difference
// in milliseconds
long Time_difference
= d1.getTime() - d0.getTime();
// Calculating the time difference in terms of minutes,
// hours, seconds, years, and days
long Seconds_difference
= TimeUnit.MILLISECONDS
.toSeconds(Time_difference)
% 60;
long Minutes_difference
= TimeUnit
.MILLISECONDS
.toMinutes(Time_difference)
% 60;
long Hours_difference
= TimeUnit
.MILLISECONDS
.toHours(Time_difference)
% 24;
long Days_difference
= TimeUnit
.MILLISECONDS
.toDays(Time_difference)
% 365;
long Years_difference
= TimeUnit
.MILLISECONDS
.toDays(Time_difference)
/ 365l;
// Printing the date difference in
// terms of years, in terms of days, in terms of hours, in terms of
// minutes, and in terms of seconds
System.out.print(
"Difference"
+ " between the two dates is: ");
// Printing the result
System.out.println(
Years_difference
+ " years, "
+ Days_difference
+ " days, "
+ Hours_difference
+ " hours, "
+ Minutes_difference
+ " minutes, "
+ Seconds_difference
+ " seconds");
}
catch (ParseException e) {
e.printStackTrace();
}
}
// Main Code
public static void main(String args[])
{
// User start_date
String startdate
= "11-01-2018 02:10:20";
// User end_date
String enddate
= "10-06-2020 06:30:50";
// Main Call
findDiff(startdate,
enddate);
}
}
输出 。
The difference between the two dates is: 2 years, 151 days, 4 hours, 20 minutes, 30 seconds
使用Java周期类
Java的Period类可以用来计算两个日子之间的区别。使用Period.between()方法可以确定两个日期之间的月、日、年的区别。上述策略的实践情况如下。
文件名：TimeDiff3.java
// Java code for the method described above
import java.time.*;
import java.util.*;
class TimeDiff3 {
// method for printing the difference between
// startdate and enddate
static void
findDifference(LocalDate startdate,
LocalDate enddate)
{
// finding the period between
// the start date and end date
Period difference
= Period
.between(startdate,
enddate);
// Printing the date difference
// in terms of years, months, and days
System.out.print(
"Difference "
+ "between the two dates is: ");
// Printing the result
System.out.printf(
"%d years, %d months"
+ " and %d days ",
difference.getYears(),
difference.getMonths(),
difference.getDays());
}
// Main Code
public static void main(String args[])
{
// Starting date
LocalDate startdate
= LocalDate.of(2017, 01, 10);
// Ending date
LocalDate enddate
= LocalDate.of(2020, 06, 10);
// Method Call
findDifference(startdate,
enddate);
}
}
输出 。
The difference between the two dates is: 3 years, 5 months, and 0 days