/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. 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.jackrabbit.core.query;
import java.io.StringReader;
import java.io.IOException;
import java.io.InputStream;
import java.util.HashMap;
import java.util.Map;
import javax.jcr.RepositoryException;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerConfigurationException;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.TransformerFactoryConfigurationError;
import javax.xml.transform.sax.SAXResult;
import javax.xml.transform.sax.SAXSource;
import org.apache.jackrabbit.core.query.lucene.FieldNames;
import org.apache.jackrabbit.core.state.PropertyState;
import org.apache.jackrabbit.core.value.BLOBFileValue;
import org.apache.jackrabbit.core.value.InternalValue;
import org.xml.sax.InputSource;
import org.xml.sax.helpers.DefaultHandler;
/**
* Extracts texts from HTML documents. It uses nekohtml library.
*/
public class HTMLTextFilter implements TextFilter {
private HTMLParser parser;
private SAXResult result;
private Transformer transformer;
/**
* @return <code>true</code> for <code>text/xml</code>, <code>false</code>
* otherwise.
*/
public boolean canFilter(String mimeType) {
return "text/html".equalsIgnoreCase(mimeType);
}
/**
* Returns a map with a single entry for field {@link FieldNames#FULLTEXT}.
*
* @param data object containing RTF document data
* @param encoding text encoding is not used, since it is specified in the
* data.
* @return a map with a single Reader value for field {@link
* FieldNames#FULLTEXT}.
* @throws RepositoryException if data is a multi-value property or if the
* content can't be extracted
*/
public Map doFilter(PropertyState data, String encoding)
throws RepositoryException {
if (parser == null) {
initParser();
}
InternalValue[] values = data.getValues();
if (values.length > 0) {
final BLOBFileValue blob = (BLOBFileValue) values[0].internalValue();
LazyReader reader = new LazyReader() {
protected void initializeReader() throws IOException {
InputStream in;
try {
in = blob.getStream();
} catch (RepositoryException e) {
throw new IOException(e.getMessage());
}
try {
SAXSource source =
new SAXSource(parser,
new InputSource(in));
transformer.transform(source, result);
String text = parser.getContents();
delegate = new StringReader(text);
} catch (TransformerException e) {
throw new IOException(e.getMessage());
} finally {
in.close();
}
}
};
Map result = new HashMap();
result.put(FieldNames.FULLTEXT, reader);
return result;
} else {
// multi value not supported
throw new RepositoryException("Multi-valued binary properties not supported.");
}
}
/**
* Inits the parser engine
*
* @throws javax.jcr.RepositoryException If some error happens
*/
private void initParser() throws javax.jcr.RepositoryException {
try {
TransformerFactory factory = TransformerFactory.newInstance();
transformer = factory.newTransformer();
parser = new HTMLParser();
result = new SAXResult(new DefaultHandler());
} catch (TransformerConfigurationException e) {
throw new RepositoryException(e);
} catch (TransformerFactoryConfigurationError e) {
throw new RepositoryException(e);
}
}
}