/*
* Copyright 2007 The Fornax Project Team, including 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.sculptor.framework.xml;
import java.io.IOException;
import java.io.InputStream;
import org.xml.sax.EntityResolver;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
/**
* This class is used for loading XML schemas or DTDs from classpath.
* The last part, the file name after the last /, of the systemId is
* used together with a resouce prefix (e.g. schemas/) to locate the
* resource in classpath.
*
*/
public class ClassloaderEntityResolver implements EntityResolver {
private String resourceNamePrefix = ""; // root of classpath
private ClassLoader classLoader = ClassloaderEntityResolver.class.getClassLoader();
/**
* Constructor without resource name prefix, i.e. the resource
* is located in the root of the classpath.
*
*/
public ClassloaderEntityResolver() {
}
/**
* @param resourceNamePrefix custom prefix of the resources, e.g. "schemas/"
*/
public ClassloaderEntityResolver(String resourceNamePrefix) {
this.resourceNamePrefix = resourceNamePrefix;
}
public void setClassLoader(ClassLoader classLoader) {
this.classLoader = classLoader;
}
public InputSource resolveEntity(String publicId, String systemId)
throws SAXException, IOException {
if (systemId == null) {
return null;
}
try {
String resourceName = resolveResourceName(systemId);
InputStream inputStream =
classLoader.getResourceAsStream(resourceName);
if (inputStream == null) {
return null;
}
return new InputSource(inputStream);
} catch (Exception e) {
// No action; just let the null InputSource pass through
return null;
}
}
private String resolveResourceName(String systemId) {
int i = systemId.lastIndexOf('/');
String name;
if (i == -1) {
name = systemId;
} else {
name = systemId.substring(i+1);
}
return (resourceNamePrefix + name);
}
}