/*
* $Id: ModularTilesInitializer.java 1297705 2012-03-06 20:44:30Z nlebas $
*
* 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.tiles.extras.module;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import java.util.jar.Attributes;
import java.util.jar.Manifest;
import javax.servlet.ServletContext;
import org.apache.tiles.definition.DefinitionsFactoryException;
import org.apache.tiles.request.ApplicationContext;
import org.apache.tiles.request.ApplicationResource;
import org.apache.tiles.request.reflect.ClassUtil;
import org.apache.tiles.request.servlet.wildcard.WildcardServletApplicationContext;
import org.apache.tiles.startup.TilesInitializer;
/**
* Loads Tiles modules, initializes them and destroy them at the end.<br>
* It loads all META-INF/MANIFEST.MF files, checks for the "Tiles-Initializer"
* property that must contain a valid class name of a {@link TilesInitializer}.
* After that, initializes all found initializers, one by one. When the
* {@link #destroy()} method is called, all the initializers are then destroyed.
*
* @version $Rev: 1297705 $ $Date: 2012-03-06 21:44:30 +0100 (Tue, 06 Mar 2012) $
* @since 2.2.1
*/
public class ModularTilesInitializer implements TilesInitializer {
/**
* The initializers to use.
*/
private List<TilesInitializer> initializers;
/** {@inheritDoc} */
public void initialize(ApplicationContext preliminaryContext) {
ApplicationContext applicationContext = new WildcardServletApplicationContext(
(ServletContext) preliminaryContext.getContext());
loadInitializers(applicationContext);
for (TilesInitializer initializer : initializers) {
initializer.initialize(preliminaryContext);
}
}
/** {@inheritDoc} */
public void destroy() {
for (TilesInitializer initializer : initializers) {
initializer.destroy();
}
}
/**
* Load all the initializers from manifest files.
*
* @param applicationContext The application context.
*/
private void loadInitializers(ApplicationContext applicationContext) {
initializers = new ArrayList<TilesInitializer>();
try {
Collection<ApplicationResource> resources = applicationContext
.getResources("classpath*:META-INF/MANIFEST.MF");
ApplicationResource mainResource = applicationContext.getResource("/META-INF/MANIFEST.MF");
if (mainResource != null) {
resources.add(mainResource);
}
for (ApplicationResource resource : resources) {
InputStream stream = resource.getInputStream();
try {
Manifest manifest = new Manifest(stream);
Attributes attributes = manifest.getMainAttributes();
if (attributes != null) {
String initializerName = attributes.getValue("Tiles-Initializer");
if (initializerName != null) {
TilesInitializer initializer = (TilesInitializer) ClassUtil
.instantiate(initializerName);
initializers.add(initializer);
}
}
} finally {
stream.close();
}
}
} catch (IOException e) {
throw new DefinitionsFactoryException("Error getting manifest files", e);
}
}
}