/*
* Copyright 2010 JBoss Inc
*
* 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.jbpm.designer.web.plugin.impl;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.Collection;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Hashtable;
import java.util.Map;
import java.util.Set;
import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
import javax.xml.stream.XMLInputFactory;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamReader;
import org.jbpm.designer.util.ConfigurationProvider;
import org.jbpm.designer.web.plugin.IDiagramPlugin;
import org.jbpm.designer.web.plugin.IDiagramPluginFactory;
import org.jbpm.designer.web.plugin.IDiagramPluginService;
import org.osgi.framework.BundleContext;
import org.osgi.framework.BundleReference;
import org.osgi.framework.InvalidSyntaxException;
import org.osgi.framework.ServiceReference;
import org.osgi.util.tracker.ServiceTracker;
import org.osgi.util.tracker.ServiceTrackerCustomizer;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* A service to manage plugins in the platform.
*
* @author Antoine Toulme
*/
public class PluginServiceImpl implements IDiagramPluginService {
private static PluginServiceImpl _instance = null;
/**
* @param context the context needed for initialization
* @return the singleton of PluginServiceImpl
*/
public static IDiagramPluginService getInstance(
ServletContext context) {
if (_instance == null) {
_instance = new PluginServiceImpl(context);
}
return _instance;
}
/**
* The default local plugins, available to the public
* so that the default profile can provision its plugins.
* Consumers through OSGi should use the service tracker
* to get the plugins they need.
*/
private static Map<String, IDiagramPlugin> LOCAL = null;
/**
* Initialize the local plugins registry
* @param context the servlet context necessary to grab
* the files inside the servlet.
* @return the set of local plugins organized by name
*/
public static Map<String, IDiagramPlugin>
getLocalPluginsRegistry(ServletContext context) {
if (LOCAL == null) {
LOCAL = initializeLocalPlugins(context);
}
return LOCAL;
}
private static Logger _logger = LoggerFactory.getLogger(PluginServiceImpl.class);
private static Map<String, IDiagramPlugin> initializeLocalPlugins(ServletContext context) {
Map<String, IDiagramPlugin> local = new HashMap<String, IDiagramPlugin>();
//we read the plugins.xml file and make sense of it.
FileInputStream fileStream = null;
try {
try {
fileStream = new FileInputStream(new StringBuilder(context.getRealPath("/"))
.append(ConfigurationProvider.getInstance().getDesignerContext()).
append("js").append("/").append("Plugins").append("/").
append("plugins.xml").toString());
} catch (FileNotFoundException e) {
throw new RuntimeException(e);
}
XMLInputFactory factory = XMLInputFactory.newInstance();
XMLStreamReader reader = factory.createXMLStreamReader(fileStream, "UTF-8");
while(reader.hasNext()) {
if (reader.next() == XMLStreamReader.START_ELEMENT) {
if ("plugin".equals(reader.getLocalName())) {
String source = null, name = null;
boolean core = false;
for (int i = 0 ; i < reader.getAttributeCount() ; i++) {
if ("source".equals(reader.getAttributeLocalName(i))) {
source = reader.getAttributeValue(i);
} else if ("name".equals(reader.getAttributeLocalName(i))) {
name = reader.getAttributeValue(i);
} else if ("core".equals(reader.getAttributeLocalName(i))) {
core = Boolean.parseBoolean(reader.getAttributeValue(i));
}
}
Map<String, Object> props = new HashMap<String, Object>();
while(reader.hasNext()) {
int ev = reader.next();
if (ev == XMLStreamReader.START_ELEMENT) {
if ("property".equals(reader.getLocalName())) {
String key = null, value = null;
for (int i = 0 ; i < reader.getAttributeCount() ; i++) {
if ("name".equals(reader.getAttributeLocalName(i))) {
key = reader.getAttributeValue(i);
} else if ("value".equals(reader.getAttributeLocalName(i))) {
value = reader.getAttributeValue(i);
}
}
if(key != null & value != null)
props.put(key, value);
}
} else if (ev == XMLStreamReader.END_ELEMENT) {
if ("plugin".equals(reader.getLocalName())) {
break;
}
}
}
local.put(name, new LocalPluginImpl(name, source, context, core, props));
}
}
}
} catch (XMLStreamException e) {
_logger.error(e.getMessage(), e);
throw new RuntimeException(e); // stop initialization
} finally {
if (fileStream != null) { try { fileStream.close(); } catch(IOException e) {}};
}
return local;
}
private Map<String, IDiagramPlugin> _registry = new HashMap<String, IDiagramPlugin>();
private Set<IDiagramPluginFactory> _factories = new HashSet<IDiagramPluginFactory>();
/**
* Private constructor to make sure we respect the singleton
* pattern.
* @param context the servlet context
*/
private PluginServiceImpl(ServletContext context) {
_registry.putAll(getLocalPluginsRegistry(context));
// if we are in the OSGi world:
if (getClass().getClassLoader() instanceof BundleReference) {
final BundleContext bundleContext = ((BundleReference) getClass().getClassLoader()).getBundle().getBundleContext();
ServiceReference[] sRefs = null;
try {
sRefs = bundleContext.getServiceReferences(IDiagramPluginFactory.class.getName(), null);
} catch (InvalidSyntaxException e) {
}
if (sRefs != null) {
for (ServiceReference sRef : sRefs) {
IDiagramPluginFactory service = (IDiagramPluginFactory) bundleContext.getService(sRef);
_factories.add(service);
}
}
ServiceTrackerCustomizer cust = new ServiceTrackerCustomizer() {
public void removedService(ServiceReference reference, Object service) {
}
public void modifiedService(ServiceReference reference, Object service) {
}
public Object addingService(ServiceReference reference) {
IDiagramPluginFactory service = (IDiagramPluginFactory) bundleContext.getService(reference);
_factories.add(service);
return service;
}
};
ServiceTracker tracker = new ServiceTracker(bundleContext,
IDiagramPluginFactory.class.getName(), cust);
tracker.open();
//make the service available to consumers as well.
bundleContext.registerService(IDiagramPluginService.class.getName(), this,
new Hashtable());
}
}
private Map<String, IDiagramPlugin> assemblePlugins(HttpServletRequest request) {
Map<String, IDiagramPlugin> plugins = new HashMap<String, IDiagramPlugin>(_registry);
for (IDiagramPluginFactory factory : _factories) {
for (IDiagramPlugin p : factory.getPlugins(request)) {
plugins.put(p.getName(), p);
}
}
return plugins;
}
public Collection<IDiagramPlugin> getRegisteredPlugins(HttpServletRequest request) {
return assemblePlugins(request).values();
}
public IDiagramPlugin findPlugin(HttpServletRequest request, String name) {
return assemblePlugins(request).get(name);
}
}