Java Calendar 计算两个时间相隔天数
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
/**
* @author Saffi
* @date 2017-10-25
*/
public class testDays {
/**
* @param args
* @throws ParseException
*/
public static void main(String[] args) throws ParseException {
//定义时间格式年月日 时分秒
SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
Date d1=sdf.parse("2014-09-15 00:00:00");
Date d2=sdf.parse("2017-10-25 00:00:00");
//方法一：日期格式的计算
System.out.println(daysBetween(d1,d2));
//方法二：字符串的日期格式的计算
System.out.println(daysBetween("2014-09-15 00:00:00","2017-10-25 00:00:00"));
}
/**
* 日期格式的计算
* @param smdate 较小的时间
* @param bdate 较大的时间
* @return 相差天数
* @throws ParseException
*/
public static int daysBetween(Date smdate,Date bdate) throws ParseException
{
SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd");
smdate=sdf.parse(sdf.format(smdate));
bdate=sdf.parse(sdf.format(bdate));
Calendar cal = Calendar.getInstance();
cal.setTime(smdate);
long time1 = cal.getTimeInMillis();
cal.setTime(bdate);
long time2 = cal.getTimeInMillis();
long between_days=(time2-time1)/(1000*3600*24);
return Integer.parseInt(String.valueOf(between_days));
}
/**
*字符串的日期格式的计算
* @param smdate 较小的时间
* @param bdate 较大的时间
* @return 相差天数
* @throws ParseException
*/
public static int daysBetween(String smdate,String bdate) throws ParseException{
SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd");
Calendar cal = Calendar.getInstance();
cal.setTime(sdf.parse(smdate));
long time1 = cal.getTimeInMillis();
cal.setTime(sdf.parse(bdate));
long time2 = cal.getTimeInMillis();
long between_days=(time2-time1)/(1000*3600*24);
return Integer.parseInt(String.valueOf(between_days));
}
}