https://xerces.apache.org/xerces2-j/: Xerces2 is the next generation of high performance, fully compliant XML parsers in the Apache Xerces family. This new version of Xerces introduces the Xerces Native Interface (XNI), a complete framework for building parser components and configurations that is extremely modular and easy to program. The Apache Xerces2 parser is the reference implementation of XNI but other parser components, configurations, and parsers can be written using the Xerces Native Interface. For complete design and implementation documents, refer to the XNI Manual. Xerces2 is a fully conforming XML Schema 1.0 processor. A partial experimental implementation of the XML Schema 1.1 Structures and Datatypes Working Drafts (December 2009) and an experimental implementation of the XML Schema Definition Language (XSD): Component Designators (SCD) Candidate Recommendation (January 2010) are provided for evaluation. For more information, refer to the XML Schema page. Xerces2 also provides a complete implementation of the Document Object Model Level 3 Core and Load/Save W3C Recommendations and provides a complete implementation of the XML Inclusions (XInclude) W3C Recommendation. It also provides support for OASIS XML Catalogs v1.1. Xerces2 is able to parse documents written according to the XML 1.1 Recommendation, except that it does not yet provide an option to enable normalization checking as described in section 2.13 of this specification. It also handles namespaces according to the XML Namespaces 1.1 Recommendation, and will correctly serialize XML 1.1 documents if the DOM level 3 load/save APIs are in use. 
/*
 * 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.impl;

import java.io.IOException;

import org.apache.xerces.xni.XNIException;
import org.apache.xerces.xni.grammars.XMLDTDDescription;
import org.apache.xerces.xni.parser.XMLEntityResolver;
import org.apache.xerces.xni.parser.XMLInputSource;


This interface extends XMLEntityResolver providing
a method to resolve external subsets for documents which do not 
explicitly provide one. The application can register an object that 
implements this interface with the parser configuration. If registered, 
it will be queried to locate an external subset when none is provided, 
even for documents that do not contain DOCTYPE declarations. If the 
registered external subset resolver does not provide an external subset
for a given document, it should return null.


Author:Michael Glavassevich, IBM
@xerces.internal
Version:$Id: ExternalSubsetResolver.java 446761 2006-09-15 21:59:29Z mrglavas $
/**
 * <p>This interface extends <code>XMLEntityResolver</code> providing
 * a method to resolve external subsets for documents which do not 
 * explicitly provide one. The application can register an object that 
 * implements this interface with the parser configuration. If registered, 
 * it will be queried to locate an external subset when none is provided, 
 * even for documents that do not contain DOCTYPE declarations. If the 
 * registered external subset resolver does not provide an external subset
 * for a given document, it should return <code>null</code>.</p>
 *
 * @xerces.internal

 * 
 * @author Michael Glavassevich, IBM
 *
 * @version $Id: ExternalSubsetResolver.java 446761 2006-09-15 21:59:29Z mrglavas $
 */
public interface ExternalSubsetResolver 
    extends XMLEntityResolver {
	
    //
    // 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.


Params:
  • grammarDescription – a description of the DTD
Throws:
  • XNIException – Thrown on general error.
  • IOException –  Thrown if resolved entity stream cannot be
                     opened or some other i/o error occurs.
/**
     * <p>Locates an external subset for documents which do not explicitly
     * provide one. If no external subset is provided, this method should
     * return <code>null</code>.</p>
     *
     * @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;

} // interface ExternalSubsetResolver