/*
* Copyright 2011 Google Inc.
*
* 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 com.google.gwt.util.tools.shared;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
/**
* Utility class to generate MD5 hashes using per-thread MD5
* {@link MessageDigest} instance.
*/
public class Md5Utils {
/**
* Per thread MD5 instance.
*/
private static final ThreadLocal<MessageDigest> perThreadMd5 =
new ThreadLocal<MessageDigest>() {
@Override
protected MessageDigest initialValue() {
try {
return MessageDigest.getInstance("MD5");
} catch (NoSuchAlgorithmException e) {
throw new RuntimeException("MD5 implementation not found", e);
}
};
};
/**
* Generate MD5 digest.
*
* @param input input data to be hashed.
* @return MD5 digest.
*/
public static byte[] getMd5Digest(byte[] input) {
MessageDigest md5 = perThreadMd5.get();
md5.reset();
md5.update(input);
return md5.digest();
}
}