Java日期循环，Java获取当月的第一天和最后一天

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++; } }