com.sun.xml.xsom.parser.JAXPParser Maven / Gradle / Ivy
/*
* Copyright (c) 1997, 2022 Oracle and/or its affiliates. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Distribution License v. 1.0, which is available at
* http://www.eclipse.org/org/documents/edl-v10.php.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
package com.sun.xml.xsom.parser;
import java.io.IOException;
import java.net.URL;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.xml.XMLConstants;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;
import org.xml.sax.*;
import org.xml.sax.helpers.XMLFilterImpl;
import com.sun.xml.xsom.impl.parser.Messages;
/**
* Standard XMLParser implemented by using JAXP.
*
* @author
* Kohsuke Kawaguchi ([email protected])
*/
public class JAXPParser implements XMLParser {
private static final Logger LOGGER = Logger.getLogger(JAXPParser.class.getName());
private final SAXParserFactory factory;
/**
* Creates a new JAXPParser that uses the given SAXParserFactory
* for creating new XMLReaders.
*
* The caller needs to configure
* it properly with security features initialized by setting
* XMLConstants.FEATURE_SECURE_PROCESSING feature.
* Also don't forget to call setNamespaceAware(true)
* or you'll see some strange errors.
*/
public JAXPParser( SAXParserFactory factory ) {
factory.setNamespaceAware(true); // just in case
this.factory = factory;
}
public void parse( InputSource source, ContentHandler handler,
ErrorHandler errorHandler, EntityResolver entityResolver )
throws SAXException, IOException {
try {
SAXParser saxParser = allowFileAccess(factory.newSAXParser(), false);
XMLReader reader = new XMLReaderEx(saxParser.getXMLReader());
reader.setContentHandler(handler);
if(errorHandler!=null)
reader.setErrorHandler(errorHandler);
if(entityResolver!=null)
reader.setEntityResolver(entityResolver);
reader.parse(source);
} catch( ParserConfigurationException e ) {
// in practice this won't happen
SAXParseException spe = new SAXParseException(e.getMessage(),null,e);
errorHandler.fatalError(spe);
throw spe;
}
}
private static SAXParser allowFileAccess(SAXParser saxParser, boolean disableSecureProcessing) throws SAXException {
// if feature secure processing enabled, nothing to do, file is allowed,
// or user is able to control access by standard JAXP mechanisms
if (disableSecureProcessing) {
return saxParser;
}
try {
saxParser.setProperty(XMLConstants.ACCESS_EXTERNAL_SCHEMA, "file");
LOGGER.log(Level.FINE, Messages.format(Messages.JAXP_SUPPORTED_PROPERTY, XMLConstants.ACCESS_EXTERNAL_SCHEMA));
} catch (SAXException ignored) {
// nothing to do; support depends on version JDK or SAX implementation
LOGGER.log(Level.CONFIG, Messages.format(Messages.JAXP_UNSUPPORTED_PROPERTY, XMLConstants.ACCESS_EXTERNAL_SCHEMA), ignored);
}
return saxParser;
}
/**
* XMLReader with improved error message for entity resolution failure.
*
* TODO: this class is completely stand-alone, so it shouldn't be
* an inner class.
*/
private static class XMLReaderEx extends XMLFilterImpl {
private Locator locator;
XMLReaderEx( XMLReader parent ) {
this.setParent(parent);
}
/**
* Resolves entities and reports user-friendly error messages.
*
*
* Some XML parser (at least Xerces) does not report much information
* when it fails to resolve an entity, which is often quite
* frustrating. For example, if you are behind a firewall and the
* schema contains a reference to www.w3.org, and there is no
* entity resolver, the parser will just throw an IOException
* that doesn't contain any information about where that reference
* occurs nor what it is accessing.
*
*
* By implementing an EntityResolver and resolving the reference
* by ourselves, we can report an error message with all the
* necessary information to fix the problem.
*
*
* Note that we still need to the client-specified entity resolver
* to let the application handle entity resolution. Here we just catch
* an IOException and add more information.
*/
@Override
public InputSource resolveEntity(String publicId, String systemId) throws SAXException {
try {
InputSource is=null;
// ask the client-specified entity resolver first
if( this.getEntityResolver()!=null)
is = this.getEntityResolver().resolveEntity(publicId,systemId);
if( is!=null ) return is; // if that succeeds, fine.
// rather than returning null, resolve it now
// so that we can detect errors.
is = new InputSource( new URL(systemId).openStream() );
is.setSystemId(systemId);
is.setPublicId(publicId);
return is;
} catch( IOException e ) {
// catch this error and provide a nice error message, rather than
// just throwing this IOException.
SAXParseException spe = new SAXParseException(
Messages.format(Messages.ERR_ENTITY_RESOLUTION_FAILURE,
systemId, e.toString()), // use the toString method to get the class name
locator, e );
if(this.getErrorHandler()!=null)
this.getErrorHandler().fatalError(spe);
throw spe;
}
}
@Override
public void setDocumentLocator(Locator locator) {
super.setDocumentLocator(locator);
this.locator = locator;
}
}
}