java生成唯一ID简单方法

通过计算机名字和时间戳来生成一个唯一的ID

public static String generateRefID() {
		Date now = new Date();
		SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMddHHmmssSSS");
		Properties prop = new Properties(System.getProperties());
		String userName = prop.getProperty("user.name");
		String refId = "ST_" + userName + "_" + sdf.format(now);
		return refId;
	}