关于java的日期运算问题

Question

我没有用calendar。SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd");
Date d = df.parse(strDate);
long lDate;
lDate=d.getTime()+(1000L*3600L*24L*X);
d=new Date(lDate);

Answer 1

谢谢了，但是我想用calendar来写，因为用Date来写，JBuilder会警告。继续等待

Answer 2

import java.util.*;public class CalendarTest {
    private GregorianCalendar d;
    
    public CalendarTest(){
        d = new GregorianCalendar();
    }
    
    public void add(int days){
        d.add(Calendar.DAY_OF_MONTH, days);
    }
    public String toString(){
        String date;
        date = d.get(Calendar.YEAR) + "年";
        date += d.get(Calendar.MONTH) + "月";
        date += d.get(Calendar.DAY_OF_MONTH) + "日";
        return date;        
    }    
    
    public static void main(String[] args) {
        CalendarTest ct = new CalendarTest();       
        System.out.println( ct );
        ct.add(-60);    
        System.out.println( ct );
        
    }    
}

Answer 3

Date dd = new Date();
Calendar cal = Calendar.getInstance();
cal.setTime(dd);
int X = 10;
cal.add(Calendar.DATE,(-1)*X);
dd = cal.getTime();
System.out.println(dd);

Answer 4

看看我的日期相关功能类吧！
http://expert.csdn.net/Expert/topic/2961/2961038.xml?temp=.7358667

Answer 5

Calendar c = new Calendar.getInstance();
c.add(Calendar.DAY_OF_YEAR,-x);