求一个月有几周

int year = 2013;
		int month= 12 ;
		Calendar c_begin = new GregorianCalendar();
		Calendar c_end = new GregorianCalendar();
		c_begin.set(year, month - 1, 1); // 当月第一天
		c_end.set(year, month, 1); // 当月最后一天 +1
		List<Date> objList = new ArrayList<Date>();
		Map<String, Object> objMap = new HashMap<String, Object>();
		// 计划当前月计划的月份中，对应的有几个周
		if (c_begin.get(Calendar.DAY_OF_WEEK) == Calendar.SUNDAY) {
			objList.add(new java.sql.Date(c_begin.getTimeInMillis()));
			objList.add(new java.sql.Date(c_begin.getTimeInMillis()));
		}else{
			objList.add(new java.sql.Date(c_begin.getTimeInMillis()));
		}
		c_begin.add(Calendar.DAY_OF_YEAR, 1);
		while (c_begin.before(c_end)) {

			if (c_begin.get(Calendar.DAY_OF_WEEK) == Calendar.SUNDAY||c_begin.get(Calendar.DAY_OF_WEEK) == Calendar.MONDAY) {
				objList.add(new java.sql.Date(c_begin.getTimeInMillis()));
			}
			//System.out.println(c_begin.getTimeInMillis()/3600000/24+"---"+c_end.getTimeInMillis()/3600000/24);
			if(c_begin.get(Calendar.DAY_OF_WEEK) != Calendar.SUNDAY&&c_begin.getTimeInMillis()/3600000/24+1==c_end.getTimeInMillis()/3600000/24){
				objList.add(new java.sql.Date(c_begin.getTimeInMillis()));
			}
			c_begin.add(Calendar.DAY_OF_YEAR, 1);
		}
		if (objMap != null && objMap.get(String.valueOf(objMap.size())) != null) {
			c_end.set(year, month, 0);
			Timestamp c = new Timestamp(c_end.getTimeInMillis());
			SimpleDateFormat dateFm = new SimpleDateFormat("yyyy-MM-dd");
			String ss = dateFm.format(c);
			objMap.put(String.valueOf(objMap.size()), objMap.get(String.valueOf(objMap.size())) + "&" + ss);
		}
		//System.out.println(objList.toString());
		for(int i=0;i<objList.size();i=i+2){
			objMap.put(String.valueOf((i+2)/2), objList.get(i).toString()+"&"+ objList.get(i+1).toString());
			System.out.println(String.valueOf((i+2)/2)+"---"+objList.get(i).toString()+"&"+ objList.get(i+1).toString());
		}