/*
* 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.tuscany.sca.binding.comet.runtime;
import java.util.HashMap;
import java.util.Map;
import org.apache.tuscany.sca.host.http.ServletHost;
import org.apache.tuscany.sca.interfacedef.Operation;
import org.apache.tuscany.sca.runtime.RuntimeEndpoint;
import org.atmosphere.cpr.AtmosphereServlet;
/**
* This class is used to create two servlets: one exposing all the comet
* services, the other one exposing the javascript toolkit. Exposing all comet
* services through a single servlet is needed as the browsers are undergone by
* the two http connection limit so all comet services should send their
* responses via the same http connection to the same client. Dispatching to the
* corresponding endpoint and operation is done internally using Jersey RESTful
* Web Services integration with the AtmosphereServlet. The Javascript toolkit
* servlet is unique as it is not tied to any of the services - it offers a
* global API.
*/
public final class ServletFactory {
/**
* Init-param key for the AtmosphereServlet defining where to look for
* Jersey classes.
*/
private static final String PACKAGE_KEY = "com.sun.jersey.config.property.packages";
/**
* Package of the class handling dispatching to endpoints.
*/
private static final String PACKAGE_VALUE = "org.apache.tuscany.sca.binding.comet.runtime.handler";
/**
* Package of the class handling Javascript toolkit retrieval.
*/
private static final String JS_PACKAGE_VALUE = "org.apache.tuscany.sca.binding.comet.runtime.javascript";
/**
* Property in the ServletContext where endpoints are added incrementally as
* the Tuscany runtime calls the CometServiceBindingProvider for each comet
* service.
*/
public static final String ENDPOINTS_KEY = "org.apache.tuscany.sca.binding.comet.endpoints";
/**
* Property in the ServletContext where operations are added incrementally
* as the CometServiceBindingProvider is calling the registerServlet method
* for each comet service method.
*/
public static final String OPERATIONS_KEY = "org.apache.tuscany.sca.binding.comet.operations";
/**
* Path where services will be exposed.
*/
public static final String PATH = "/tuscany-comet/*";
/**
* Path where Javascript toolkit will be exposed.
*/
public static final String JS_PATH = "/org.apache.tuscany.sca.cometComponentContext.js/*";
/**
* The servlet that is exposing the comet services.
*/
private static AtmosphereServlet cometServlet = null;
/**
* The servlet that is exposing the Javascript toolkit.
*/
private static AtmosphereServlet javascriptServlet = null;
/**
* Private constructor for the singleton class.
*/
private ServletFactory() {
}
/**
* Method called by CometServiceBindingProvider for each endpoint in order
* to create the two singleton servlets.
*
* @param servletHost the underlying servlet host
*/
public static synchronized void registerServlet(final ServletHost servletHost) {
if (ServletFactory.cometServlet == null) {
ServletFactory.cometServlet = new AtmosphereServlet();
ServletFactory.cometServlet.addInitParameter(ServletFactory.PACKAGE_KEY, ServletFactory.PACKAGE_VALUE);
servletHost.addServletMapping(ServletFactory.PATH, ServletFactory.cometServlet);
// store operations and corresponding endpoint in the ServletContext
// so that they can be retrieved from inside the web service methods
final Map<String, RuntimeEndpoint> endpoints = new HashMap<String, RuntimeEndpoint>();
ServletFactory.cometServlet.getServletContext().setAttribute(ServletFactory.ENDPOINTS_KEY, endpoints);
final Map<String, Operation> operations = new HashMap<String, Operation>();
ServletFactory.cometServlet.getServletContext().setAttribute(ServletFactory.OPERATIONS_KEY, operations);
}
if (ServletFactory.javascriptServlet == null) {
ServletFactory.javascriptServlet = new AtmosphereServlet();
ServletFactory.javascriptServlet.addInitParameter(ServletFactory.PACKAGE_KEY,
ServletFactory.JS_PACKAGE_VALUE);
servletHost.addServletMapping(ServletFactory.JS_PATH, ServletFactory.javascriptServlet);
}
}
/**
* Method called by CometServiceBindingProvider for each endpoint operation
* in order to store all the operations the servlet will serve.
*
* @param endpoint the endpoint
* @param operation the operation
*/
public static synchronized void addOperation(final RuntimeEndpoint endpoint, final Operation operation) {
final String url = "/" + endpoint.getService().getName() + "/" + operation.getName();
final Map<String, RuntimeEndpoint> endpoints =
(Map<String, RuntimeEndpoint>)ServletFactory.cometServlet.getServletContext()
.getAttribute(ServletFactory.ENDPOINTS_KEY);
endpoints.put(url, endpoint);
final Map<String, Operation> operations =
(Map<String, Operation>)ServletFactory.cometServlet.getServletContext()
.getAttribute(ServletFactory.OPERATIONS_KEY);
operations.put(url, operation);
}
/**
* Method called by CometServiceBindingProvider for each endpoint operation
* in order to remove the two servlets.
*
* @param servletHost the underlying servlet host
*/
public static synchronized void unregisterServlet(final ServletHost servletHost) {
servletHost.removeServletMapping(ServletFactory.PATH);
servletHost.removeServletMapping(ServletFactory.JS_PATH);
}
}