Md5Util.java

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

    public class Md5Util {
        public static String hex(byte[] array) {
            StringBuffer sb = new StringBuffer();
            for (int i = 0; i < array.length; ++i) {
                sb.append(Integer.toHexString((array[i]
                        & 0xFF) | 0x100).substring(1,3));
            }
            return sb.toString();
        }

        public static String convertToMd5(String message) {
            try {
                MessageDigest md = MessageDigest.getInstance("MD5");
                return hex(md.digest(message.getBytes("CP1252")));
            } catch (NoSuchAlgorithmException e) {
                // TODO: handle error
            } catch (UnsupportedEncodingException e) {
                // TODO: handle error
            }
            return null;
        }
    }

usage.java

String md5hash = Md5Util.convertToMd5("[email protected]");