Check sum for an InputStream
/*
* 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.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.util.zip.Adler32;
import java.util.zip.CheckedInputStream;
/*
* 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.
*/
/**
* implements checksum related utilities
*
* @author <a href="mailto:taylor@apache.org">David Sean Taylor </a>
* @version $Id: ChecksumHelper.java 516448 2007-03-09 16:25:47Z ate $
*/
final class ChecksumHelper
{
public static long getChecksum(InputStream is)
{
CheckedInputStream cis = null;
long checksum = 0;
try
{
cis = new CheckedInputStream(is, new Adler32());
byte[] tempBuf = new byte[128];
while (cis.read(tempBuf) >= 0)
{
}
checksum = cis.getChecksum().getValue();
}
catch (IOException e)
{
checksum = 0;
}
finally
{
if (cis != null)
{
try
{
cis.close();
}
catch (IOException ioe)
{
}
}
}
return checksum;
}
}
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