几个代码片段-计算程序运行时间+获得当前目录+生成MD5

计算程序运行时间

	long startTime = System.currentTimeMillis();

	System.out.println("程序运行时间： " + (System.currentTimeMillis() - startTime) + "ms");

获得当前目录

	System.getProperty("user.dir")

生成MD5

	public String genMd5(final String input) {

		try {

			MessageDigest m = MessageDigest.getInstance("MD5");

			m.reset();

			m.update(input.getBytes());

			byte[] digest = m.digest();

			BigInteger bigInt = new BigInteger(1, digest);

			String hashtext = bigInt.toString(16);

			while (hashtext.length() < 32) {

				hashtext = "0" + hashtext;

			}

			return hashtext;

		} catch (NoSuchAlgorithmException e) {

			e.printStackTrace();

		}

		return null;

	}