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A processor for parsing, validating, serializing and manipulating XML, written in Java
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/*
* 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.xerces.util;
import java.io.IOException;
import java.io.InputStream;
import java.io.Reader;
import org.apache.xerces.impl.ExternalSubsetResolver;
import org.apache.xerces.impl.XMLEntityDescription;
import org.apache.xerces.xni.XMLResourceIdentifier;
import org.apache.xerces.xni.XNIException;
import org.apache.xerces.xni.grammars.XMLDTDDescription;
import org.apache.xerces.xni.parser.XMLInputSource;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import org.xml.sax.ext.EntityResolver2;
/**
* This class wraps a SAX entity resolver (EntityResolver2) in an XNI entity resolver.
*
* @author Michael Glavassevich, IBM
*
* @version $Id$
*/
public class EntityResolver2Wrapper
implements ExternalSubsetResolver {
//
// Data
//
/** An instance of SAX2 Extensions 1.1's EntityResolver2. */
protected EntityResolver2 fEntityResolver;
//
// Constructors
//
/** Default constructor. */
public EntityResolver2Wrapper() {}
/**
* Creates a new instance wrapping the given SAX entity resolver.
*
* @param entityResolver the SAX entity resolver to wrap
*/
public EntityResolver2Wrapper(EntityResolver2 entityResolver) {
setEntityResolver(entityResolver);
} // (EntityResolver2)
//
// Public methods
//
/**
* Sets the SAX entity resolver wrapped by this object.
*
* @param entityResolver the SAX entity resolver to wrap
*/
public void setEntityResolver(EntityResolver2 entityResolver) {
fEntityResolver = entityResolver;
} // setEntityResolver(EntityResolver2)
/**
* Returns the SAX entity resolver wrapped by this object.
*
* @return the SAX entity resolver wrapped by this object
*/
public EntityResolver2 getEntityResolver() {
return fEntityResolver;
} // getEntityResolver():EntityResolver2
//
// ExternalSubsetResolver methods
//
/**
* Locates an external subset for documents which do not explicitly
* provide one. If no external subset is provided, this method should
* return null
.
*
* @param grammarDescription a description of the DTD
*
* @throws XNIException Thrown on general error.
* @throws IOException Thrown if resolved entity stream cannot be
* opened or some other i/o error occurs.
*/
public XMLInputSource getExternalSubset(XMLDTDDescription grammarDescription)
throws XNIException, IOException {
if (fEntityResolver != null) {
String name = grammarDescription.getRootName();
String baseURI = grammarDescription.getBaseSystemId();
// Resolve using EntityResolver2
try {
InputSource inputSource = fEntityResolver.getExternalSubset(name, baseURI);
return (inputSource != null) ? createXMLInputSource(inputSource, baseURI) : null;
}
// error resolving external subset
catch (SAXException e) {
Exception ex = e.getException();
if (ex == null) {
ex = e;
}
throw new XNIException(ex);
}
}
// unable to resolve external subset
return null;
} // getExternalSubset(XMLDTDDescription):XMLInputSource
//
// XMLEntityResolver methods
//
/**
* Resolves an external parsed entity. If the entity cannot be
* resolved, this method should return null.
*
* @param resourceIdentifier contains the physical co-ordinates of the resource to be resolved
*
* @throws XNIException Thrown on general error.
* @throws IOException Thrown if resolved entity stream cannot be
* opened or some other i/o error occurs.
*/
public XMLInputSource resolveEntity(XMLResourceIdentifier resourceIdentifier)
throws XNIException, IOException {
if (fEntityResolver != null) {
String pubId = resourceIdentifier.getPublicId();
String sysId = resourceIdentifier.getLiteralSystemId();
String baseURI = resourceIdentifier.getBaseSystemId();
String name = null;
if (resourceIdentifier instanceof XMLDTDDescription) {
name = "[dtd]";
}
else if (resourceIdentifier instanceof XMLEntityDescription) {
name = ((XMLEntityDescription) resourceIdentifier).getEntityName();
}
// When both pubId and sysId are null, the user's entity resolver
// can do nothing about it. We'd better not bother calling it.
// This happens when the resourceIdentifier is a GrammarDescription,
// which describes a schema grammar of some namespace, but without
// any schema location hint. -Sg
if (pubId == null && sysId == null) {
return null;
}
// Resolve using EntityResolver2
try {
InputSource inputSource =
fEntityResolver.resolveEntity(name, pubId, baseURI, sysId);
return (inputSource != null) ? createXMLInputSource(inputSource, baseURI) : null;
}
// error resolving entity
catch (SAXException e) {
Exception ex = e.getException();
if (ex == null) {
ex = e;
}
throw new XNIException(ex);
}
}
// unable to resolve entity
return null;
} // resolveEntity(XMLResourceIdentifier):XMLInputSource
/**
* Creates an XMLInputSource from a SAX InputSource.
*/
private XMLInputSource createXMLInputSource(InputSource source, String baseURI) {
String publicId = source.getPublicId();
String systemId = source.getSystemId();
String baseSystemId = baseURI;
InputStream byteStream = source.getByteStream();
Reader charStream = source.getCharacterStream();
String encoding = source.getEncoding();
XMLInputSource xmlInputSource =
new XMLInputSource(publicId, systemId, baseSystemId);
xmlInputSource.setByteStream(byteStream);
xmlInputSource.setCharacterStream(charStream);
xmlInputSource.setEncoding(encoding);
return xmlInputSource;
} // createXMLInputSource(InputSource,String):XMLInputSource
} // class EntityResolver2Wrapper