org.eclipse.rdf4j.rio.helpers.XMLReaderBasedParser Maven / Gradle / Ivy
/*******************************************************************************
* Copyright (c) 2019 Eclipse RDF4J contributors.
*
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Distribution License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/org/documents/edl-v10.php.
*
* SPDX-License-Identifier: BSD-3-Clause
*******************************************************************************/
package org.eclipse.rdf4j.rio.helpers;
import java.util.Collection;
import java.util.Collections;
import java.util.Set;
import org.eclipse.rdf4j.common.xml.XMLReaderFactory;
import org.eclipse.rdf4j.model.ValueFactory;
import org.eclipse.rdf4j.rio.RioSetting;
import org.xml.sax.SAXException;
import org.xml.sax.SAXNotRecognizedException;
import org.xml.sax.SAXNotSupportedException;
import org.xml.sax.XMLReader;
/**
* Base class for Rio parsers that are based on a SAX {@link XMLReader}.
*
* @author Jeen Broekstra
*/
public abstract class XMLReaderBasedParser extends AbstractRDFParser {
private final static Set> compulsoryXmlFeatureSettings = Set.of(
XMLParserSettings.SECURE_PROCESSING,
XMLParserSettings.DISALLOW_DOCTYPE_DECL,
XMLParserSettings.EXTERNAL_GENERAL_ENTITIES,
XMLParserSettings.EXTERNAL_PARAMETER_ENTITIES,
XMLParserSettings.LOAD_EXTERNAL_DTD
);
protected XMLReaderBasedParser(ValueFactory f) {
super(f);
}
/**
* Returns a collection of settings that will always be set as XML parser properties using
* {@link XMLReader#setProperty(String, Object)}
*
* Subclasses can override this to specify more supported settings.
*
* @return A collection of {@link RioSetting}s that indicate which properties will always be setup using
* {@link XMLReader#setProperty(String, Object)}.
*/
public Collection> getCompulsoryXmlPropertySettings() {
return Collections.>emptyList();
}
/**
* Returns a collection of settings that will always be set as XML parser features using
* {@link XMLReader#setFeature(String, boolean)}.
*
* Subclasses can override this to specify more supported settings.
*
* @return A collection of {@link RioSetting}s that indicate which boolean settings will always be setup using
* {@link XMLReader#setFeature(String, boolean)}.
*/
public Collection> getCompulsoryXmlFeatureSettings() {
return Collections.unmodifiableSet(compulsoryXmlFeatureSettings);
}
/**
* Returns a collection of settings that will be used, if set in {@link #getParserConfig()}, as XML parser
* properties using {@link XMLReader#setProperty(String, Object)}
*
* Subclasses can override this to specify more supported settings.
*
* @return A collection of {@link RioSetting}s that indicate which properties can be setup using
* {@link XMLReader#setProperty(String, Object)}.
*/
public Collection> getOptionalXmlPropertySettings() {
return Collections.>emptyList();
}
/**
* Returns a collection of settings that will be used, if set in {@link #getParserConfig()}, as XML parser features
* using {@link XMLReader#setFeature(String, boolean)}.
*
* Subclasses can override this to specify more supported settings.
*
* @return A collection of {@link RioSetting}s that indicate which boolean settings can be setup using
* {@link XMLReader#setFeature(String, boolean)}.
*/
public Collection> getOptionalXmlFeatureSettings() {
return Collections.>emptyList();
}
/**
* Creates an XML Reader configured using the current parser settings.
*
* @return a configured {@link XMLReader}
* @throws SAXException if an error occurs during configuration.
*/
protected XMLReader getXMLReader() throws SAXException {
XMLReader xmlReader;
if (getParserConfig().isSet(XMLParserSettings.CUSTOM_XML_READER)) {
xmlReader = getParserConfig().get(XMLParserSettings.CUSTOM_XML_READER);
} else {
xmlReader = XMLReaderFactory.createXMLReader();
}
// Set all compulsory feature settings, using the defaults if they are
// not explicitly set
for (RioSetting aSetting : getCompulsoryXmlFeatureSettings()) {
try {
xmlReader.setFeature(aSetting.getKey(), getParserConfig().get(aSetting));
} catch (SAXNotRecognizedException e) {
reportWarning(String.format("%s is not a recognized SAX feature.", aSetting.getKey()));
} catch (SAXNotSupportedException e) {
reportWarning(String.format("%s is not a supported SAX feature.", aSetting.getKey()));
}
}
// Set all compulsory property settings, using the defaults if they are
// not explicitly set
for (RioSetting aSetting : getCompulsoryXmlPropertySettings()) {
try {
xmlReader.setProperty(aSetting.getKey(), getParserConfig().get(aSetting));
} catch (SAXNotRecognizedException e) {
reportWarning(String.format("%s is not a recognized SAX property.", aSetting.getKey()));
} catch (SAXNotSupportedException e) {
reportWarning(String.format("%s is not a supported SAX property.", aSetting.getKey()));
}
}
// Check for any optional feature settings that are explicitly set in
// the parser config
for (RioSetting aSetting : getOptionalXmlFeatureSettings()) {
try {
if (getParserConfig().isSet(aSetting)) {
xmlReader.setFeature(aSetting.getKey(), getParserConfig().get(aSetting));
}
} catch (SAXNotRecognizedException e) {
reportWarning(String.format("%s is not a recognized SAX feature.", aSetting.getKey()));
} catch (SAXNotSupportedException e) {
reportWarning(String.format("%s is not a supported SAX feature.", aSetting.getKey()));
}
}
// Check for any optional property settings that are explicitly set in
// the parser config
for (RioSetting aSetting : getOptionalXmlPropertySettings()) {
try {
if (getParserConfig().isSet(aSetting)) {
xmlReader.setProperty(aSetting.getKey(), getParserConfig().get(aSetting));
}
} catch (SAXNotRecognizedException e) {
reportWarning(String.format("%s is not a recognized SAX property.", aSetting.getKey()));
} catch (SAXNotSupportedException e) {
reportWarning(String.format("%s is not a supported SAX property.", aSetting.getKey()));
}
}
return xmlReader;
}
}