HashUtil.java

package de.ovgu.cide.mining.database;

import java.io.UnsupportedEncodingException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

public class HashUtil {

	private static String convertToHex(byte[] data) {
		StringBuffer buf = new StringBuffer();
		for (int i = 0; i < data.length; i++) {
			int halfbyte = (data[i] >>> 4) & 0x0F;
			int two_halfs = 0;
			do {
				if ((0 <= halfbyte) && (halfbyte <= 9))
					buf.append((char) ('0' + halfbyte));
				else
					buf.append((char) ('a' + (halfbyte - 10)));
				halfbyte = data[i] & 0x0F;
			} while (two_halfs++ < 1);
		}
		return buf.toString();
	}

	public static String MD5(String text) throws NoSuchAlgorithmException,
			UnsupportedEncodingException {
		MessageDigest md;
		md = MessageDigest.getInstance("MD5");
		byte[] md5hash = new byte[32];
		md.update(text.getBytes("iso-8859-1"), 0, text.length());
		md5hash = md.digest();
		return convertToHex(md5hash);
	}

	public static String hashId(String id) {
		try {
			return MD5(id);
		} catch (NoSuchAlgorithmException e) {
			e.printStackTrace();
			return id;
		} catch (UnsupportedEncodingException e) {
			e.printStackTrace();
			return id;
		}
	}

}