日期验证和格式化（2）

private static boolean dataStyleValidate(String date, String divideSign) {
		// divideSign is '-' or '/' or others.验证格式，闰年
		String regex = "^((((1[6-9]|[2-9]\\d)\\d{2})"
				+ divideSign
				+ "(0[13578]|1[02])"
				+ divideSign
				+ "(0[1-9]|[12]\\d|3[01]))|(((1[6-9]|[2-9]\\d)\\d{2})"
				+ divideSign
				+ "(0[13456789]|1[012])"
				+ divideSign
				+ "(0[1-9]|[12]\\d|30))|(((1[6-9]|[2-9]\\d)\\d{2})"
				+ divideSign
				+ "02"
				+ divideSign
				+ "(0[1-9]|1\\d|2[0-8]))|((([0-9]{2})(0[48]|[2468][048]|[13579][26])|((0[48]|[2468][048]|[3579][26])00))"
				+ divideSign + "02" + divideSign + "29"  + "))$";
		boolean flag = false;
		Pattern p = Pattern.compile(regex);
		Matcher matcher = p.matcher(date);
		if (matcher.find()) {
			flag = true;
		}
		return flag;
	}

	public static double round(String value, int digit) {
            //保留小数点，ROUND_DOWN位置设置四舍五入或者直接截取属性
		return new BigDecimal(value).setScale(digit, BigDecimal.ROUND_DOWN)
				.doubleValue();
	}

	public static boolean isNumber(String num) {
           //判断字符串是否是数字
		String regex = "^-?([1-9]\\d*\\.\\d*|0\\.\\d*[1-9]\\d*|0|\\.0+|0|[1-9]\\d*)$";
		boolean flag = false;
			Pattern p = Pattern.compile(regex);
			Matcher matcher = p.matcher(num);
			if (matcher.find()) {
				flag = true;
			}
		return flag;
	}

	public static Timestamp stringToTimestamp(String timestampStr, String format) {
               //转换日期的格式为特定格式
		if (timestampStr == null || timestampStr.trim().equals(" ")) {
			return null;
		}
		SimpleDateFormat dateFormat = new SimpleDateFormat(format);
		try {
			Date date = dateFormat.parse(timestampStr);
			return new Timestamp(date.getTime());
		} catch (Exception e) {
			System.out.println(e.getMessage());
		}
		return null;
	}

	public static String DoFormatDate(String dt_in, String format) {
		return (new SimpleDateFormat(format)).format(dt_in);
	}