/*
* 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.deltaspike.jpa.spi.descriptor.xml;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.util.Collections;
import java.util.Enumeration;
import java.util.LinkedList;
import java.util.List;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import org.apache.deltaspike.core.util.AggregatedClassLoader;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
abstract class DescriptorReader
{
private static final Logger LOG = Logger.getLogger(DescriptorReader.class.getName());
private final DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
protected List<Descriptor> readAllFromClassPath(String resource) throws IOException
{
List<Descriptor> result = new LinkedList<Descriptor>();
Enumeration<URL> urls = classLoader().getResources(resource);
while (urls.hasMoreElements())
{
URL u = urls.nextElement();
try
{
result.add(readFromUrl(u));
}
catch (Exception e)
{
LOG.log(Level.WARNING, "Could not load " + resource + " from " + u, e);
}
}
return Collections.unmodifiableList(result);
}
protected Descriptor readFromClassPath(String resource) throws IOException
{
return readFromUrl(classLoader().getResource(resource));
}
protected Descriptor readFromUrl(URL url) throws IOException
{
InputStream stream = url.openStream();
try
{
DocumentBuilder builder = factory.newDocumentBuilder();
return new Descriptor(builder.parse(new InputSource(stream)), url);
}
catch (SAXException e)
{
throw new RuntimeException("Failed reading XML document", e);
}
catch (ParserConfigurationException e)
{
throw new RuntimeException("Failed reading XML document", e);
}
finally
{
stream.close();
}
}
protected Descriptor read(String baseUrl, String resource) throws IOException
{
try
{
URL url = new URL(baseUrl + resource);
return readFromUrl(url);
}
catch (Exception e)
{
return readFromClassPath(resource);
}
}
protected String extractBaseUrl(URL fileUrl, String resource)
{
String file = fileUrl.toString();
return file.substring(0, file.length() - resource.length());
}
protected ClassLoader classLoader()
{
return AggregatedClassLoader.newInstance();
}
}