java生成随机密码的一个方法

/**
	 * 生成随机密码
	 * @return
	 */
	public static String makeRandNum() {
		String str = DateUtils.getCurrLongTime();
		long time = Long.parseLong(str.substring(6, 14));
		long num = (long) (Math.random() * 90000000L) + time + 100000L;
		// 判断生成的数
		String cardPass = String.valueOf(num);
		if (cardPass.length() > 8) {
			cardPass = cardPass.substring(0, 8);
		}else if(cardPass.length()<8){
			StringBuffer nameBuffer = new StringBuffer(cardPass.trim());
			while (nameBuffer.length() < 8) {
				nameBuffer.append("0");
			}
			cardPass=nameBuffer.toString();
		}
		return cardPass;
	}