Calendar

/**获得参数月份的一号及其下一个月的一号*/
	private StockDate getStockDate(String stockDate){
		String stockDateStart=stockDate+"-01";
		Calendar c=Calendar.getInstance();
		SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd");
		try {
			c.setTime(sdf.parse(stockDateStart));
		} catch (ParseException e) {
			log.error(e.getMessage(), e);
		}
		c.add(Calendar.MONTH, 1);
		String stockDateEnd=sdf.format(c.getTime());
		c.add(Calendar.MONTH, -2);
		return new StockDate(stockDateStart,stockDateEnd,sdf.format(c.getTime()));
	}