/*
* Copyright 2004-2007 the original author or authors.
*
* Licensed 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.springframework.webflow.engine.builder.model;
import java.io.IOException;
import org.springframework.core.io.ClassPathResource;
import org.springframework.core.io.Resource;
import org.springframework.core.io.ResourceLoader;
/**
* A resource loader that loads other resources relative to a Flow definition resource. Allows for easy loading of
* flow-relative resources using the standard {@link ResourceLoader} interface.
*
* @author Keith Donald
*/
class FlowRelativeResourceLoader implements ResourceLoader {
private Resource flowResource;
public FlowRelativeResourceLoader(Resource resource) {
this.flowResource = resource;
}
public ClassLoader getClassLoader() {
return flowResource.getClass().getClassLoader();
}
public Resource getResource(String location) {
if (location.startsWith(CLASSPATH_URL_PREFIX)) {
return new ClassPathResource(location.substring(CLASSPATH_URL_PREFIX.length()), getClassLoader());
} else {
return createFlowRelativeResource(location);
}
}
private Resource createFlowRelativeResource(String location) {
try {
return flowResource.createRelative(location);
} catch (IOException e) {
IllegalArgumentException iae = new IllegalArgumentException(
"Unable to access a flow relative resource at location '" + location + "'");
iae.initCause(e);
throw iae;
}
}
}