http://xml.apache.org/commons/components/external/: xml-commons provides an Apache-hosted set of DOM, SAX, and JAXP interfaces for use in other xml-based projects. Our hope is that we can standardize on both a common version and packaging scheme for these critical XML standards interfaces to make the lives of both our developers and users easier. The External Components portion of xml-commons contains interfaces that are defined by external standards organizations. For DOM, that's the W3C; for SAX it's David Megginson and sax.sourceforge.net; for JAXP it's Sun. 
/*
 * 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.
 */

// $Id: URIResolver.java 446598 2006-09-15 12:55:40Z jeremias $

package javax.xml.transform;


An object that implements this interface that can be called by the processor
to turn a URI used in document(), xsl:import, or xsl:include into a Source object.

/**
 * <p>An object that implements this interface that can be called by the processor
 * to turn a URI used in document(), xsl:import, or xsl:include into a Source object.
 */
public interface URIResolver {

    
Called by the processor when it encounters
an xsl:include, xsl:import, or document() function.

Params:
  • href – An href attribute, which may be relative or absolute.
  • base – The base URI against which the first argument will be made
absolute if the absolute URI is required.
Throws:
Returns:A Source object, or null if the href cannot be resolved,
and the processor should try to resolve the URI itself.
/**
     * Called by the processor when it encounters
     * an xsl:include, xsl:import, or document() function.
     *
     * @param href An href attribute, which may be relative or absolute.
     * @param base The base URI against which the first argument will be made
     * absolute if the absolute URI is required.
     *
     * @return A Source object, or null if the href cannot be resolved,
     * and the processor should try to resolve the URI itself.
     *
     * @throws TransformerException if an error occurs when trying to
     * resolve the URI.
     */
    public Source resolve(String href, String base)
        throws TransformerException;
}