采用MD5单向加密

	public static String getMd5(String src) throws Exception {
		Assert.notNull(src, "src must not be null.");
		MessageDigest md5 = MessageDigest.getInstance("MD5");
		byte[] target = md5.digest(src.getBytes("UTF-8"));
		StringBuilder sb = new StringBuilder(target.length * 2);
		String s;
		for (byte b : target) {
			s = Integer.toHexString(b & 0xff);
			if (s.length() == 1) {
				s += "0";
			}
			sb.append(s.toUpperCase());
		}
		return sb.toString();
	}