MD5 Sum
/**
* Copyright (C) 2010 Cloudfarming <info@cloudfarming.nl>
*
* Licensed under the Eclipse Public License - v 1.0 (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.eclipse.org/legal/epl-v10.html
*
* 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 nl.cloudfarming.client.util;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
/**
*
* @author Timon Veenstra
*/
public class MD5Sum {
/**
* Create a MD5 checksum for a file
*
* @param filename
* @return md5sum
* @throws Exception
*/
public static byte[] createChecksum(InputStream fis) throws NoSuchAlgorithmException, IOException {
if (fis == null) {
throw new FileNotFoundException("InputStream cannot be read");
}
byte[] buffer = new byte[1024];
MessageDigest complete = MessageDigest.getInstance("MD5");
int numRead;
do {
numRead = fis.read(buffer);
if (numRead > 0) {
complete.update(buffer, 0, numRead);
}
} while (numRead != -1);
fis.close();
return complete.digest();
}
static final String HEXES = "0123456789abcdef";
/**
* convert byte into a hax encoded string
*
* @param raw
* @return
*/
public static String getHex(byte[] raw) {
if (raw == null) {
return null;
}
final StringBuilder hex = new StringBuilder(2 * raw.length);
for (final byte b : raw) {
hex.append(HEXES.charAt((b & 0xF0) >> 4)).append(HEXES.charAt((b & 0x0F)));
}
return hex.toString();
}
}
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