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/*******************************************************************************
* Copyright (c) 2009, 2017 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
* Mykola Nikishov - extract MD5 checksum calculation
*******************************************************************************/
package org.eclipse.equinox.internal.p2.repository.helpers;
import java.io.*;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
public class ChecksumProducer {
public static String computeMD5(File file) {
if (file == null || file.isDirectory() || !file.exists())
return null;
InputStream fis = null;
try {
MessageDigest md5Checker = MessageDigest.getInstance("MD5"); //$NON-NLS-1$
fis = new BufferedInputStream(new FileInputStream(file));
int read = -1;
final int bufferSize = 4 * 1024;
byte[] buffer = new byte[bufferSize];
while ((read = fis.read(buffer, 0, bufferSize)) != -1) {
md5Checker.update(buffer, 0, read);
}
byte[] digest = md5Checker.digest();
StringBuffer buf = new StringBuffer();
for (int i = 0; i < digest.length; i++) {
if ((digest[i] & 0xFF) < 0x10)
buf.append('0');
buf.append(Integer.toHexString(digest[i] & 0xFF));
}
return buf.toString();
} catch (NoSuchAlgorithmException e) {
return null;
} catch (IOException e) {
return null;
} finally {
if (fis != null)
try {
fis.close();
} catch (IOException e) {
// ignore
}
}
}
}
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