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";