org.apache.tika.parser.DigestingParser Maven / Gradle / Ivy
/*
* 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.
*/
package org.apache.tika.parser;
import java.io.IOException;
import java.io.InputStream;
import org.apache.tika.exception.TikaException;
import org.apache.tika.io.TemporaryResources;
import org.apache.tika.io.TikaInputStream;
import org.apache.tika.metadata.Metadata;
import org.xml.sax.ContentHandler;
import org.xml.sax.SAXException;
public class DigestingParser extends ParserDecorator {
/**
* Interface for digester. See
* org.apache.parser.utils.CommonsDigester in tika-parsers for an
* implementation.
*/
public interface Digester {
/**
* Digests an InputStream and sets the appropriate value(s) in the metadata.
* The Digester is also responsible for marking and resetting the stream.
*
* The given stream is guaranteed to support the
* {@link InputStream#markSupported() mark feature} and the detector
* is expected to {@link InputStream#mark(int) mark} the stream before
* reading any bytes from it, and to {@link InputStream#reset() reset}
* the stream before returning. The stream must not be closed by the
* detector.
*
* @param is InputStream to digest
* @param m Metadata to set the values for
* @param parseContext ParseContext
* @throws IOException
*/
void digest(InputStream is, Metadata m, ParseContext parseContext) throws IOException;
};
/**
* Encodes byte array from a MessageDigest to String
*/
public interface Encoder {
String encode(byte[] bytes);
}
private final Digester digester;
/**
* Creates a decorator for the given parser.
*
* @param parser the parser instance to be decorated
*/
public DigestingParser(Parser parser, Digester digester) {
super(parser);
this.digester = digester;
}
@Override
public void parse(InputStream stream, ContentHandler handler, Metadata metadata, ParseContext context) throws IOException, SAXException, TikaException {
TemporaryResources tmp = new TemporaryResources();
TikaInputStream tis = TikaInputStream.get(stream, tmp);
try {
if (digester != null) {
digester.digest(tis, metadata, context);
}
super.parse(tis, handler, metadata, context);
} finally {
tmp.dispose();
}
}
}