Md5.java

/*******************************************************************************
 * Copyright (c) 2013 Chris Banes.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 ******************************************************************************/
package uk.co.senab.bitmapcache;

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

class Md5 {

    private static final char[] DIGITS = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a',
            'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r',
            's', 't', 'u', 'v', 'w', 'x', 'y', 'z'};

    public static String encode(String string) {
        try {
            MessageDigest digest = MessageDigest.getInstance("MD5");
            return bytesToHexString(digest.digest(string.getBytes()));
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        }
        return null;
    }

    private static String bytesToHexString(byte[] bytes) {
        final char[] buf = new char[bytes.length * 2];

        byte b;
        int c = 0;
        for (int i = 0, z = bytes.length; i < z; i++) {
            b = bytes[i];
            buf[c++] = DIGITS[(b >> 4) & 0xf];
            buf[c++] = DIGITS[b & 0xf];
        }

        return new String(buf);
    }

}