/**
* 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.marmotta.platform.sparql.services.sparqlio.sparqlhtml;
import org.apache.marmotta.platform.core.api.config.ConfigurationService;
import org.apache.marmotta.platform.core.util.CDIContext;
import org.jdom2.Document;
import org.jdom2.output.Format;
import org.jdom2.output.XMLOutputter;
import org.jdom2.transform.JDOMResult;
import org.openrdf.query.resultio.BooleanQueryResultFormat;
import org.openrdf.query.resultio.BooleanQueryResultWriter;
import org.openrdf.query.resultio.sparqlxml.SPARQLBooleanXMLWriter;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import javax.xml.transform.Source;
import javax.xml.transform.Templates;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerConfigurationException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.stream.StreamSource;
import java.io.BufferedWriter;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.nio.charset.Charset;
/**
* Add file description here!
* <p/>
* User: sschaffe
*/
public class SPARQLBooleanHTMLWriter implements BooleanQueryResultWriter {
private static final Logger log = LoggerFactory.getLogger(SPARQLBooleanHTMLWriter.class);
private OutputStream out;
private ByteArrayOutputStream xmlOut;
private SPARQLBooleanXMLWriter xmlWriter;
private Templates stylesheet;
public SPARQLBooleanHTMLWriter(OutputStream out) {
this.out = out;
this.xmlOut = new ByteArrayOutputStream();
this.xmlWriter = new SPARQLBooleanXMLWriter(xmlOut);
Source s_stylesheet = new StreamSource(SPARQLBooleanHTMLWriter.class.getResourceAsStream("style.xsl"));
try {
stylesheet = TransformerFactory.newInstance().newTemplates(s_stylesheet);
} catch (TransformerConfigurationException e) {
log.error("could not compile stylesheet for rendering SPARQL results; result display not available!");
}
}
/**
* Gets the query result format that this writer uses.
*/
@Override
public BooleanQueryResultFormat getBooleanQueryResultFormat() {
return new BooleanQueryResultFormat("SPARQL/HTML","text/html", Charset.forName("UTF-8"), "html");
}
/**
* Writes the specified boolean value.
*/
@Override
public void write(boolean value) throws IOException {
xmlWriter.write(value);
byte[] queryResult = xmlOut.toByteArray();
// get server uri
String server_uri = CDIContext.getInstance(ConfigurationService.class).getServerUri();
BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(out));
try {
Source input = new StreamSource(new ByteArrayInputStream(queryResult));
Transformer transformer = stylesheet.newTransformer();
transformer.setParameter("serverurl", server_uri);
JDOMResult result = new JDOMResult();
transformer.transform(input,result);
Document output = result.getDocument();
XMLOutputter printer = new XMLOutputter(Format.getPrettyFormat());
printer.output(output, writer);
writer.flush();
} catch (Exception ex) {
throw new IOException("error while transforming XML results to HTML",ex);
} finally {
writer.close();
}
}
}