Question

任何人都可以告诉如何减去字符串＆＃34;＆＃34;来自＆＃34;今天＆＃34;得到天差。

import java.text.*;
import java.util.*;


public class Main {
public static void main(String args[]){


SimpleDateFormat sdf=new SimpleDateFormat("yyyy/MM/dd");
Calendar cal=Calendar.getInstance();
String today=sdf.format(cal.getTime());
System.out.println(today);
cal.add(Calendar.DATE, 20);
String After=sdf.format(cal.getTime());
System.out.println(After);

}
}

Answer 1

使用java8会更容易，你不需要减去代表日期的长值，然后再改回天，小时和分钟。

Date today= LocalDate.now();
Date futureDate = LocalDate.now().plusDays(1);
long days = Period.between(today, futureDate).getDays();

Period＆amp; ＃java8

中提供了LocalDate类

LocalDate docs

LocalDate是一个表示日期的不可变日期时间对象，通常被视为年月日。其他日期字段，例如也可以访问日期，星期和星期。对于例如，值“2007年10月2日”可以存储在LocalDate中。

如果您不使用java8，请使用joda-time library的org.joda.time.Days实用程序来计算

Days day = Days.daysBetween(startDate, endDate);
int days = d.getDays();

Answer 2

使用JodaTime，以防您没有Java 8

String timeValue = "2014/11/11";
DateTimeFormatter parseFormat = new DateTimeFormatterBuilder().appendPattern("yyyy/MM/dd").toFormatter();
LocalDate startDate = LocalDate.parse(timeValue, parseFormat);
LocalDate endDate = startDate.plusDays(20);

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

Period p = new Period(startDate, endDate);
System.out.println("Days = " + p.getDays());
System.out.println("Weeks = " + p.getWeeks());
System.out.println("Months = " + p.getMonths());

哪些输出......

2014-11-11; 2014-12-01
Days = 6
Weeks = 2
Months = 0

Answer 3

试试这个......

它可以帮助你。

import java.util.Date;
import java.util.GregorianCalendar;

// compute the difference between two dates.

public class DateDiff {
  public static void main(String[] av) {
    /** The date at the end of the last century */
    Date d1 = new GregorianCalendar(2010, 10, 10, 11, 59).getTime();

    /** Today's date */
    Date today = new Date();

    // Get msec from each, and subtract.
    long diff = today.getTime() - d1.getTime();

    System.out.println("The 21st century (up to " + today + ") is "
        + (diff / (1000 * 60 * 60 * 24)) + " days old.");
  }
}

Answer 4

这可能对你有所帮助..

SimpleDateFormat sdf=new SimpleDateFormat("yyyy/MM/dd");
    Calendar cal=Calendar.getInstance();
    String today=sdf.format(cal.getTime());
    System.out.println(today);

    cal.add(Calendar.DATE, 20);
    String After=sdf.format(cal.getTime());
    System.out.println(After);

    Date d1 = null;
    Date d2 = null;

    SimpleDateFormat format = new SimpleDateFormat("yyyy/MM/dd");

    try {
        d1 = format.parse(today);
        d2 = format.parse(After);
    } catch (ParseException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

    long diff = d2.getTime() - d1.getTime();

    long diffDays = diff / (24 * 60 * 60 * 1000);

    System.out.println("Difference is "+diffDays+" Days");

减去日期并获得天数差异。如何减去它们？

4 个答案: