package org.apache.maven.it;
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.
*/
import java.io.File;
import java.io.FileInputStream;
import java.security.DigestInputStream;
import java.security.MessageDigest;
/**
* @author Benjamin Bentmann
*/
class ItUtils
{
public static String calcHash( File file, String algo )
throws Exception
{
MessageDigest digester = MessageDigest.getInstance( algo );
FileInputStream is = new FileInputStream( file );
try
{
DigestInputStream dis = new DigestInputStream( is, digester );
for ( byte[] buffer = new byte[1024 * 4]; dis.read( buffer ) >= 0; )
{
// just read it
}
}
finally
{
is.close();
}
byte[] digest = digester.digest();
StringBuffer hash = new StringBuffer( digest.length * 2 );
for ( int i = 0; i < digest.length; i++ )
{
int b = digest[i] & 0xFF;
if ( b < 0x10 )
{
hash.append( '0' );
}
hash.append( Integer.toHexString( b ) );
}
return hash.toString();
}
}