java 任意两个时间差，天数，小时数，分钟数，秒数

原地址：http://ju.outofmemory.cn/entry/53112

在java 编程中，不可避免用到计算时间差。前面我写过几篇文章，关于java 时间计算的，还有timezone 转换的文章，但没有这么具体到相差到天数，小时，分钟，秒数都列出来的情况，所以这里再总结下。

1. 用JDK 自带API 实现。

2.利用 joda time library 来实现.

首先看看用JDK 自带API 是如何实现的。

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;

public class DateTimeUtils {

public static void main(String[] args) {

DateTimeUtils obj = new DateTimeUtils();
SimpleDateFormat simpleDateFormat =
new SimpleDateFormat("dd/M/yyyy hh:mm:ss");

try {

Date date1 = simpleDateFormat.parse("10/10/2013 11:30:10");
Date date2 = simpleDateFormat.parse("13/10/2013 20:35:55");

obj.printDifference(date1, date2);

} catch (ParseException e) {
e.printStackTrace();
}

}

//1 minute = 60 seconds
//1 hour = 60 x 60 = 3600
//1 day = 3600 x 24 = 86400
public void printDifference(Date startDate, Date endDate){

//milliseconds
long different = endDate.getTime() - startDate.getTime();

System.out.println("startDate : " + startDate);
System.out.println("endDate : "+ endDate);
System.out.println("different : " + different);

long secondsInMilli = 1000;
long minutesInMilli = secondsInMilli * 60;
long hoursInMilli = minutesInMilli * 60;
long daysInMilli = hoursInMilli * 24;

long elapsedDays = different / daysInMilli;
different = different % daysInMilli;

long elapsedHours = different / hoursInMilli;
different = different % hoursInMilli;

long elapsedMinutes = different / minutesInMilli;
different = different % minutesInMilli;

long elapsedSeconds = different / secondsInMilli;

System.out.printf(
"%d days, %d hours, %d minutes, %d seconds%n",
elapsedDays,
elapsedHours, elapsedMinutes, elapsedSeconds);

}

}

输出结果如下:

startDate : Thu Oct 10 11:30:10 SGT 2013
endDate : Sun Oct 13 20:35:55 SGT 2013
different : 291945000
days, 9 hours, 5 minutes, 45 seconds

看看这里的输出，并没有年，月的差别。手工计算是件麻烦事，所以一般采用了 joda time library 来实现，

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;

import org.joda.time.Interval;
import org.joda.time.Period;

public class DateTimeUtils {

public static void main(String[] args) {

DateTimeUtils obj = new DateTimeUtils();
SimpleDateFormat simpleDateFormat =
new SimpleDateFormat("dd/M/yyyy hh:mm:ss");

try {

Date date1 = simpleDateFormat.parse("10/10/2013 11:30:10");
Date date2 = simpleDateFormat.parse("13/11/2014 20:35:55");

obj.printDifference(date1, date2);

} catch (ParseException e) {
e.printStackTrace();
}

}

public void printDifference(Date startDate, Date endDate){

Interval interval =
new Interval(startDate.getTime(), endDate.getTime());
Period period = interval.toPeriod();

System.out.printf(
"%d years, %d months, %d days, %d hours, %d minutes, %d seconds%n",
period.getYears(), period.getMonths(), period.getDays(),
period.getHours(), period.getMinutes(), period.getSeconds());

}
}

看看结果

years, 1 months, 3 days, 9 hours, 5 minutes, 45 seconds