package org.jtheque.modules.impl;
/*
* Copyright JTheque (Baptiste Wicht)
*
* 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.
*/
import org.jtheque.core.Core;
import org.jtheque.modules.ModuleDescription;
import org.jtheque.modules.Repository;
import org.jtheque.utils.StringUtils;
import org.jtheque.utils.annotations.GuardedBy;
import org.jtheque.utils.annotations.ThreadSafe;
import org.jtheque.utils.bean.InternationalString;
import org.jtheque.utils.bean.Version;
import org.jtheque.utils.collections.CollectionUtils;
import org.jtheque.utils.io.FileUtils;
import org.jtheque.xml.utils.XML;
import org.jtheque.xml.utils.XMLException;
import org.jtheque.xml.utils.XMLReader;
import org.slf4j.LoggerFactory;
import org.w3c.dom.Node;
import java.util.List;
import java.util.Map;
/**
* A reader for repository XML file.
*
* @author Baptiste Wicht
*/
@ThreadSafe
final class RepositoryReader {
@GuardedBy("RepositoryReader.class")
private static Repository repository;
/**
* Utility class, not instantiable.
*/
private RepositoryReader() {
throw new AssertionError();
}
/**
* Return the cached repository from the given URL.
*
* @param strUrl The URL of the repository.
*
* @return The cached repository.
*/
static Repository getCachedRepository(String strUrl) {
synchronized (RepositoryReader.class) {
if (repository == null) {
repository = read(strUrl);
}
return repository;
}
}
/**
* Read a repository file.
*
* @param strUrl The URL of the repository file.
*
* @return The repository.
*/
private static Repository read(String strUrl) {
XMLReader<Node> reader = XML.newJavaFactory().newReader();
try {
reader.openURL(strUrl);
return new RepositoryImpl(readTitle(reader), readApplication(reader), readModules(reader));
} catch (XMLException e) {
LoggerFactory.getLogger(RepositoryReader.class).error("Unable to get information from repository", e);
} finally {
FileUtils.close(reader);
}
return null;
}
/**
* Read the application informations from the reader.
*
* @param reader The reader to use.
*
* @return The name of the application.
*
* @throws XMLException If an error occurs during the XML reading process.
*/
private static String readApplication(XMLReader<Node> reader) throws XMLException {
return reader.readString("application", reader.getRootElement());
}
/**
* Read the modules informations from the reader.
*
* @param reader The reader to use.
*
* @return The List of modules contained in the repository.
*
* @throws XMLException If an error occurs during the XML reading process.
*/
private static List<ModuleDescription> readModules(XMLReader<Node> reader) throws XMLException {
List<ModuleDescription> descriptions = CollectionUtils.newList();
for (Object currentNode : reader.getNodes("modules/module", reader.getRootElement())) {
Version coreVersion =
StringUtils.isEmpty(reader.readString("core", currentNode)) ?
Core.VERSION :
Version.get(reader.readString("core", currentNode));
Map<String, String> resources = CollectionUtils.newHashMap(5);
for (Node child : reader.getNodes("description/*", currentNode)) {
resources.put(child.getNodeName(), child.getTextContent());
}
descriptions.add(new ModuleDescriptionImpl(
reader.readString("id", currentNode),
reader.readString("name", currentNode),
new InternationalString(resources),
reader.readString("versions", currentNode),
coreVersion));
}
return descriptions;
}
/**
* Read the title of the repository from the reader.
*
* @param reader The reader to use.
*
* @return Read the title of the repository.
*
* @throws XMLException If an error occurs during the XML reading process.
*/
private static InternationalString readTitle(XMLReader<Node> reader) throws XMLException {
Map<String, String> resources = CollectionUtils.newHashMap(5);
for (Node child : reader.getNodes("title/*", reader.getRootElement())) {
resources.put(child.getNodeName(), child.getTextContent());
}
return new InternationalString(resources);
}
}