/**
* Licensed to Apereo under one or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information regarding copyright ownership. Apereo
* 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 the
* following location:
*
* <p>http://www.apache.org/licenses/LICENSE-2.0
*
* <p>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.apereo.portal.xml;
import java.io.IOException;
import java.io.InputStream;
import javax.xml.transform.Source;
import javax.xml.transform.TransformerException;
import javax.xml.transform.URIResolver;
import javax.xml.transform.stream.StreamSource;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.core.io.Resource;
import org.springframework.core.io.ResourceLoader;
/**
* A URIResolver that uses a provided Spring {@link ResourceLoader} to resolve references in a XSL
* document. Assumes that the provided 'base + href' argument or if base is null 'href' argument can
* be correctly resolved by the {@link ResourceLoader}
*
*/
public class ResourceLoaderURIResolver implements URIResolver {
protected final Logger logger = LoggerFactory.getLogger(this.getClass());
protected final ResourceLoader resourceLoader;
public ResourceLoaderURIResolver(ResourceLoader resourceLoader) {
this.resourceLoader = resourceLoader;
}
@Override
public Source resolve(String href, String base) throws TransformerException {
final Resource resolvedResource = resolveResource(href, base);
return createSource(resolvedResource, base);
}
/** Create a {@link Source} from the specified {@link Resource} */
protected Source createSource(final Resource resolvedResource, String base)
throws TransformerException {
final InputStream resourceStream;
try {
resourceStream = resolvedResource.getInputStream();
} catch (IOException e) {
throw new TransformerException("Failed to get InputStream for " + resolvedResource, e);
}
final StreamSource streamSource = new StreamSource(resourceStream);
streamSource.setSystemId(base);
return streamSource;
}
/** Resolve the requested {@link Resource} */
protected Resource resolveResource(String href, String base) throws TransformerException {
final Resource resolvedResource;
if (base != null) {
final Resource baseResource = this.resourceLoader.getResource(base);
try {
resolvedResource = baseResource.createRelative(href);
} catch (IOException e) {
throw new TransformerException(
"Failed to find '" + href + "' relative to: " + baseResource, e);
}
this.logger.debug(
"Created resource {} for href: {} and base: {}",
new Object[] {resolvedResource, href, baseResource});
} else {
resolvedResource = this.resourceLoader.getResource(href);
this.logger.debug("Created resource {} for href: {}", resolvedResource, href);
}
return resolvedResource;
}
}