JAva先月、前年の日付を取得

/**
	 * 
	 * @Description:          
	 * @param
	 * @return String
	 * @throws
	 * @author 
	 * @createtime 
	 */
	public String getHbDate(String currentDate) {
		 
		SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
		Date date = null;
		String monthFormat;
		try {
			date = sdf.parse(currentDate + "-" + "01");
		} catch (ParseException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		Calendar c = Calendar.getInstance();
		c.setTime(date);
		c.add(Calendar.MONTH, -1);
		int month = c.get(Calendar.MONTH) + 1;
		if(month<=9) {
			 monthFormat="0"+month;
		}else {
			monthFormat=String.valueOf(month);
		}
		String hbDate = c.get(Calendar.YEAR) + "-"
				+ monthFormat+"-01";
		return hbDate;
	}
	/**
	 * 
	 * @Description:         
	 * @param
	 * @return String
	 * @throws
	 * @author 
	 * @createtime 
	 */
	public String getTbDate(String currentDate) {
		SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
		Date date = null;
		String monthFormat;
		try {
			date = sdf.parse(currentDate + "-" + "01");
		} catch (ParseException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		Calendar c = Calendar.getInstance();
		c.setTime(date);
		c.add(Calendar.YEAR, -1);
		int month = c.get(Calendar.MONTH) + 1;
		if(month<=9) {
			 monthFormat="0"+month;
		}else {
			monthFormat=String.valueOf(month);
		}
		String tbDate = c.get(Calendar.YEAR) + "-"
				+ monthFormat+"-01";
		return tbDate;
	}