【转】本月的第一天和最后一天

迈不过友情╰ 2022-04-15 07:38 387阅读 0赞

1、Java日期循环
    
    SimpleDateFormat formater = new SimpleDateFormat("yyyy-MM-dd");
    
    String   dateStr1="2008-3-16"; 
    
    String      dateStr2="2008-3-24"; 
    
    java.util.Date dateBegin=formater.parse(dateStr1);
    
    java.util.Date dateEnd=formater.parse(dateStr2);             
    
    
    
    Calendar   ca=Calendar.getInstance(); 
    
    while(dateBegin.compareTo(dateEnd)<=0){             
    
                 ca.setTime(dateBegin);   
    
                  ca.add(ca.DATE,1);//把dateBegin加上1天然后重新赋值给date1   
    
                  dateBegin=ca.getTime();       
    
           }
    
    2、Java获取当月的第一天和最后一天
    
    Calendar cal = Calendar.getInstance(); 
    
    SimpleDateFormat datef=new SimpleDateFormat("yyyy-MM-dd");
                 //当前月的最后一天   
                 cal.set( Calendar.DATE, 1 );
                 cal.roll(Calendar.DATE, - 1 );
                 Date endTime=cal.getTime();
                 String endTime1=datef.format(endTime)+" 23:59:59";
                  //当前月的第一天          
                 cal.set(GregorianCalendar.DAY_OF_MONTH, 1); 
                  Date beginTime=cal.getTime();
                 String beginTime1=datef.format(beginTime)+" 00:00:00";
    
    
    //循环输出日期
    public static void main(String[] arg) throws Exception {
            GregorianCalendar g = new GregorianCalendar();
            g.setTime(new Date());
            int day = g.get(Calendar.DAY_OF_YEAR);
            int year = g.get(Calendar.YEAR);
            for (int i = 0; i < 400; i++) {
                SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
                String formatTime = sdf.format(g.getTime());
                System.out.println(formatTime);
                if(g.get(Calendar.YEAR) > year) {
                    day = 0;
                    year = g.get(Calendar.YEAR);
                }
                g.set(Calendar.DAY_OF_YEAR, day + 1);
                day++;
            }
        }