FileSummation.java

/*
 * Copyright 2014 Ricardo Lorenzo<unshakablespirit@gmail.com>
 *
 *    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.
 */

/*
 * FileSummation class
 *
 * This program is free software: you can redistribute it and/or modify it under the terms of the
 * GNU General Public License as published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without
 * even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along with this program. If
 * not, see <http://www.gnu.org/licenses/>.
 *
 * Author: Ricardo Lorenzo <unshakablespirit@gmail.com>
 */
package utils.file;

/**
 * Enables you to compare files using MD5 summation
 *
 * @author: Ricardo Lorenzo
 */

import java.io.*;
import java.math.BigInteger;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

public class FileSummation {
    public static boolean compare(final byte[] data1, final byte[] data2) throws NoSuchAlgorithmException, IOException {
        if(getMD5Summation(data1).equals(getMD5Summation(data2))) {
            return true;
        }
        return false;
    }

    public static boolean compare(final File file1, final File file2) throws NoSuchAlgorithmException, IOException {
        if(getMD5Summation(file1).equals(getMD5Summation(file2))) {
            return true;
        }
        return false;
    }

    public static String getMD5Summation(final byte[] data) throws NoSuchAlgorithmException, IOException {
        final InputStream is = new ByteArrayInputStream(data);
        return getMD5Summation(is);
    }

    public static String getMD5Summation(final File file) throws NoSuchAlgorithmException, IOException {
        final InputStream is = new FileInputStream(file);
        return getMD5Summation(is);
    }

    private static String getMD5Summation(final InputStream is) throws NoSuchAlgorithmException, IOException {
        final MessageDigest digest = MessageDigest.getInstance("MD5");
        final byte[] buffer = new byte[8192];
        int read = 0;
        try {
            while((read = is.read(buffer)) > 0) {
                digest.update(buffer, 0, read);
            }
            final byte[] _md5sum = digest.digest();
            final BigInteger bi = new BigInteger(1, _md5sum);
            return bi.toString(16);
        } finally {
            IOStreamUtils.closeQuietly(is);
        }
    }
}