Java tutorial
/******************************************************************************* * The MIT License (MIT) * * Copyright (c) 2011, 2013 OpenWorm. * http://openworm.org * * All rights reserved. This program and the accompanying materials * are made available under the terms of the MIT License * which accompanies this distribution, and is available at * http://opensource.org/licenses/MIT * * Contributors: * OpenWorm - http://openworm.org/people.html * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE * USE OR OTHER DEALINGS IN THE SOFTWARE. *******************************************************************************/ package org.geppetto.frontend; import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; import java.net.MalformedURLException; import java.net.URL; import java.nio.CharBuffer; import java.util.ArrayList; import java.util.Collection; import java.util.Collections; import java.util.List; import java.util.Properties; import java.util.concurrent.ConcurrentHashMap; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.geppetto.core.common.GeppettoExecutionException; import org.geppetto.core.common.GeppettoInitializationException; import org.geppetto.core.data.model.VariableList; import org.geppetto.core.data.model.WatchList; import org.geppetto.core.simulation.ISimulationCallbackListener; import org.geppetto.frontend.GeppettoMessageInbound.VisitorRunMode; import org.geppetto.frontend.SimulationServerConfig.ServerBehaviorModes; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.web.context.support.SpringBeanAutowiringSupport; import com.fasterxml.jackson.core.JsonProcessingException; import com.fasterxml.jackson.core.type.TypeReference; import com.fasterxml.jackson.databind.ObjectMapper; import com.google.gson.Gson; import com.google.gson.JsonArray; import com.google.gson.JsonObject; /** * Class that handles the Web Socket connections the servlet is receiving. * * * @author Jesus R. Martinez (jesus@metacell.us) * */ public class GeppettoServletController { private static Log _logger = LogFactory.getLog(GeppettoServletController.class); @Autowired private SimulationServerConfig _simulationServerConfig; private static GeppettoServletController _instance = null; private ISimulationCallbackListener _simulationCallbackListener; private final ConcurrentHashMap<String, GeppettoMessageInbound> _connections = new ConcurrentHashMap<String, GeppettoMessageInbound>(); private List<GeppettoMessageInbound> _queueUsers = new ArrayList<GeppettoMessageInbound>(); private List<GeppettoMessageInbound> _observers = new ArrayList<GeppettoMessageInbound>(); private boolean _simulationInUse = false; protected GeppettoServletController() { SpringBeanAutowiringSupport.processInjectionBasedOnCurrentContext(this); } public static GeppettoServletController getInstance() { if (_instance == null) { _instance = new GeppettoServletController(); } return _instance; } /** * Add new connection to list of current ones * * @param newVisitor * - New connection to be added to current ones */ public void addConnection(GeppettoMessageInbound newVisitor) { _connections.put(newVisitor.getConnectionID(), newVisitor); performStartUpCheck(newVisitor); } /** * Remove connection from list of current ones. * * @param exitingVisitor * - Connection to be removed */ public void removeConnection(GeppettoMessageInbound exitingVisitor) { if (_connections.contains(exitingVisitor)) { _connections.remove(exitingVisitor.getConnectionID()); // Handle operations after user closes connection postClosingConnectionCheck(exitingVisitor); } } /** * Performs start up check when new connection is established. * * @param newVisitor * - New visitor */ private void performStartUpCheck(GeppettoMessageInbound newVisitor) { if (this._simulationServerConfig.getServerBehaviorMode() == ServerBehaviorModes.OBSERVE) { // Simulation is being used, notify new user controls are // unavailable if (isSimulationInUse()) { simulationControlsUnavailable(newVisitor); } } else if (this._simulationServerConfig.getServerBehaviorMode() == ServerBehaviorModes.MULTIUSER) { int simulatorCapacity = newVisitor.getSimulationService().getSimulationCapacity(); if ((this.getConnections().size() > simulatorCapacity) && (simulatorCapacity > 1)) { int position = (this.getConnections().size() - newVisitor.getSimulationService().getSimulationCapacity()); String update = "{ \"simulatorName\":" + '"' + newVisitor.getSimulationService().getSimulatorName() + '"' + ", \"queuePosition\": " + position + "}"; _queueUsers.add(newVisitor); messageClient(null, newVisitor, OUTBOUND_MESSAGE_TYPES.SIMULATOR_FULL, update); } else { messageClient(null, newVisitor, OUTBOUND_MESSAGE_TYPES.READ_URL_PARAMETERS); } } } /** * Return all the current web socket connections * * @return */ public Collection<GeppettoMessageInbound> getConnections() { return Collections.unmodifiableCollection(_connections.values()); } /** * Attempt to load simulation * * @param simulation * - Simulation to load * @param visitor * - Visitor doing the loading */ public void load(String requestID, String simulation, GeppettoMessageInbound visitor) { // Determine current mode of Geppetto switch (_simulationServerConfig.getServerBehaviorMode()) { // Handle multi user mode case MULTIUSER: _simulationCallbackListener = new MultiuserSimulationCallback(visitor); loadInMultiUserMode(requestID, simulation, visitor); break; // Handle observe mode case OBSERVE: _simulationCallbackListener = ObservermodeSimulationCallback.getInstance(); loadInObserverMode(requestID, simulation, visitor); break; default: break; } } /** * Handle multiuser mode * * @param simulation * - Simulation to be loaded * @param visitor * - Visitor doing the loading of simulation */ private void loadInMultiUserMode(String requestID, String simulation, GeppettoMessageInbound visitor) { visitor.setIsSimulationLoaded(false); loadSimulation(requestID, simulation, visitor); } /** * Handle observer mode * * @param simulation * - Simulation to be loaded * @param visitor * - Visitor doing the loading of simulation */ private void loadInObserverMode(String requestID, String simulation, GeppettoMessageInbound visitor) { // Simulation already in use if (isSimulationInUse()) { switch (visitor.getCurrentRunMode()) { // user attempting load is already in control of simulation servlet case CONTROLLING: _simulationServerConfig.setIsSimulationLoaded(false); // Clear canvas of users connected for new model to be loaded for (GeppettoMessageInbound observer : _observers) { messageClient(null, observer, OUTBOUND_MESSAGE_TYPES.RELOAD_CANVAS); } loadSimulation(requestID, simulation, visitor); break; case WAITING: // Do Nothing break; // user attempting to load can't do so since it's not user in // control case OBSERVING: simulationControlsUnavailable(visitor); break; } } // simulation not in use else { _simulationServerConfig.setIsSimulationLoaded(false); // load simulation _simulationInUse = loadSimulation(requestID, simulation, visitor); // Simulation just got someone to control it, notify everyone else // connected that simulation controls are unavailable. for (GeppettoMessageInbound connection : getConnections()) { if (connection != visitor) { simulationControlsUnavailable(connection); } } } } /** * Load simulation * * @param simulation * - Simulation to load * @param visitor * - Visitor doing the loading of simulation * * @return {boolean} - Success or failure */ private boolean loadSimulation(String requestID, String simulation, GeppettoMessageInbound visitor) { boolean loaded = false; URL url = null; // attempt to convert simulation to URL try { url = new URL(simulation); // simulation is URL, initialize simulation services visitor.getSimulationService().init(url, requestID, _simulationCallbackListener); postLoadSimulation(requestID, visitor); loaded = true; } /* * Unable to make url from simulation, must be simulation content. URL * validity checked in GeppettoMessageInbound prior to call here */ catch (MalformedURLException e) { try { visitor.getSimulationService().init(simulation, requestID, _simulationCallbackListener); postLoadSimulation(requestID, visitor); loaded = true; } catch (GeppettoInitializationException e1) { messageClient(requestID, visitor, OUTBOUND_MESSAGE_TYPES.ERROR_LOADING_SIMULATION); loaded = false; } } catch (GeppettoInitializationException e) { messageClient(requestID, visitor, OUTBOUND_MESSAGE_TYPES.ERROR_LOADING_SIMULATION); loaded = false; } // set user as controlling visitor.setVisitorRunMode(VisitorRunMode.CONTROLLING); return loaded; } public SimulationServerConfig getSimulationServerConfig() { return _simulationServerConfig; } /** * Runs scripts that are specified in the simulation * * @param requestID * - requestID received from client * @param visitor * - Visitor loading the simulation */ private void postLoadSimulation(String requestID, GeppettoMessageInbound visitor) { messageClient(requestID, visitor, OUTBOUND_MESSAGE_TYPES.SIMULATION_LOADED); JsonObject scriptsJSON = new JsonObject(); JsonArray scriptsArray = new JsonArray(); for (URL scriptURL : visitor.getSimulationService().getScripts()) { JsonObject script = new JsonObject(); script.addProperty("script", scriptURL.toString()); scriptsArray.add(script); } scriptsJSON.add("scripts", scriptsArray); // notify client if there are scripts if (visitor.getSimulationService().getScripts().size() > 0) { messageClient(requestID, visitor, OUTBOUND_MESSAGE_TYPES.FIRE_SIM_SCRIPTS, scriptsJSON.toString()); } } /** * Start the simulation */ public void startSimulation(String requestID, GeppettoMessageInbound controllingUser) { try { controllingUser.getSimulationService().start(requestID); } catch (GeppettoExecutionException e) { throw new RuntimeException(e); } } /** * Pause the simulation */ public void pauseSimulation(String requestID, GeppettoMessageInbound controllingUser) { try { controllingUser.getSimulationService().pause(); // notify user simulation has been paused messageClient(requestID, controllingUser, OUTBOUND_MESSAGE_TYPES.SIMULATION_PAUSED); } catch (GeppettoExecutionException e) { throw new RuntimeException(e); } } /** * Stop the running simulation */ public void stopSimulation(String requestID, GeppettoMessageInbound controllingUser) { try { controllingUser.getSimulationService().stop(); // notify user simulation has been stopped messageClient(requestID, controllingUser, OUTBOUND_MESSAGE_TYPES.SIMULATION_STOPPED); } catch (GeppettoExecutionException e) { throw new RuntimeException(e); } } /** * Add visitor to list users Observing simulation * * @param observingVisitor * - Geppetto visitor joining list of simulation observers */ public void observeSimulation(String requestID, GeppettoMessageInbound observingVisitor) { _observers.add(observingVisitor); observingVisitor.setVisitorRunMode(VisitorRunMode.OBSERVING); if (!observingVisitor.getSimulationService().isRunning()) { messageClient(requestID, observingVisitor, OUTBOUND_MESSAGE_TYPES.LOAD_MODEL, getSimulationServerConfig().getLoadedScene()); } // Notify visitor they are now in Observe Mode messageClient(requestID, observingVisitor, OUTBOUND_MESSAGE_TYPES.OBSERVER_MODE); } /** * Request list of watchable variables for the simulation * * @throws JsonProcessingException */ public void listWatchableVariables(String requestID, GeppettoMessageInbound visitor) throws JsonProcessingException { // get watchable variables for the entire simulation VariableList vars = visitor.getSimulationService().listWatchableVariables(); // serialize ObjectMapper mapper = new ObjectMapper(); String serializedVars = mapper.writer().writeValueAsString(vars); // message the client with results this.messageClient(requestID, visitor, OUTBOUND_MESSAGE_TYPES.LIST_WATCH_VARS, serializedVars); } /** * Request list of forceable variables for the simulation * * @throws JsonProcessingException */ public void listForceableVariables(String requestID, GeppettoMessageInbound visitor) throws JsonProcessingException { // get forceable variables for the entire simulation VariableList vars = visitor.getSimulationService().listForceableVariables(); // serialize ObjectMapper mapper = new ObjectMapper(); String serializedVars = mapper.writer().writeValueAsString(vars); // message the client with results this.messageClient(requestID, visitor, OUTBOUND_MESSAGE_TYPES.LIST_FORCE_VARS, serializedVars); } /** * Adds watch lists with variables to be watched * * @throws GeppettoExecutionException * @throws JsonProcessingException * @throws GeppettoInitializationException */ public void addWatchLists(String requestID, String jsonLists, GeppettoMessageInbound visitor) throws GeppettoExecutionException, GeppettoInitializationException { List<WatchList> lists = null; lists = fromJSON(new TypeReference<List<WatchList>>() { }, jsonLists); visitor.getSimulationService().addWatchLists(lists); // serialize watch-lists ObjectMapper mapper = new ObjectMapper(); String serializedLists; try { serializedLists = mapper.writer().writeValueAsString(lists); } catch (JsonProcessingException e) { throw new GeppettoExecutionException(e); } // message the client the watch lists were added messageClient(requestID, visitor, OUTBOUND_MESSAGE_TYPES.SET_WATCH_LISTS, serializedLists); } /** * instructs simulation to start sending watched variables value to the * client * * @param requestID * @throws JsonProcessingException */ public void startWatch(String requestID, GeppettoMessageInbound visitor) throws JsonProcessingException { visitor.getSimulationService().startWatch(); List<WatchList> watchLists = visitor.getSimulationService().getWatchLists(); // serialize watch-lists ObjectMapper mapper = new ObjectMapper(); String serializedLists = mapper.writer().writeValueAsString(watchLists); // message the client the watch lists were started messageClient(requestID, visitor, OUTBOUND_MESSAGE_TYPES.START_WATCH, serializedLists); } /** * instructs simulation to stop sending watched variables value to the * client */ public void stopWatch(String requestID, GeppettoMessageInbound visitor) { visitor.getSimulationService().stopWatch(); // message the client the watch lists were stopped messageClient(requestID, visitor, OUTBOUND_MESSAGE_TYPES.STOP_WATCH); } /** * instructs simulation to clear watch lists */ public void clearWatchLists(String requestID, GeppettoMessageInbound visitor) { visitor.getSimulationService().clearWatchLists(); // message the client the watch lists were cleared messageClient(requestID, visitor, OUTBOUND_MESSAGE_TYPES.CLEAR_WATCH); } /** * Get simulation watch lists * * @throws JsonProcessingException */ public void getWatchLists(String requestID, GeppettoMessageInbound visitor) throws JsonProcessingException { List<WatchList> watchLists = visitor.getSimulationService().getWatchLists(); // serialize watch-lists ObjectMapper mapper = new ObjectMapper(); String serializedLists = mapper.writer().writeValueAsString(watchLists); // message the client with results this.messageClient(requestID, visitor, OUTBOUND_MESSAGE_TYPES.GET_WATCH_LISTS, serializedLists); } /** * is notified with an alert message of status of simulation. * * @param id * - ID of new Websocket connection. */ public void simulationControlsUnavailable(GeppettoMessageInbound visitor) { messageClient(null, visitor, OUTBOUND_MESSAGE_TYPES.SERVER_UNAVAILABLE); } /** * On closing a client connection (WebSocket Connection), perform check to * see if user leaving was the one in control of simulation if it was * running. * * @param id * - WebSocket ID of user closing connection */ public void postClosingConnectionCheck(GeppettoMessageInbound exitingVisitor) { if (this._simulationServerConfig.getServerBehaviorMode() == ServerBehaviorModes.MULTIUSER) { // Controlling user is leaving, but simulation might still be // running. try { // Pause running simulation upon controlling user's exit exitingVisitor.getSimulationService().stop(); } catch (GeppettoExecutionException e) { _logger.error("Unable to stop simulation for exiting user"); } int simulatorCapacity = exitingVisitor.getSimulationService().getSimulationCapacity(); if (this.getConnections().size() == simulatorCapacity) { GeppettoMessageInbound nextVisitorInLine = this._queueUsers.get(0); messageClient(null, nextVisitorInLine, OUTBOUND_MESSAGE_TYPES.SERVER_AVAILABLE); } } else { /* * If the exiting visitor was running the simulation, notify all the * observing visitors that the controls for the simulation became * available */ if (exitingVisitor.getCurrentRunMode() == GeppettoMessageInbound.VisitorRunMode.CONTROLLING) { // Controlling user is leaving, but simulation might still be // running. try { if (exitingVisitor.getSimulationService().isRunning()) { // Pause running simulation upon controlling user's exit exitingVisitor.getSimulationService().stop(); } } catch (GeppettoExecutionException e) { _logger.error("Unable to stop simulation for exiting user"); } // Notify all observers for (GeppettoMessageInbound visitor : _observers) { // visitor.setVisitorRunMode(VisitorRunMode.DEFAULT); // send message to alert client of server availability messageClient(null, visitor, OUTBOUND_MESSAGE_TYPES.SERVER_AVAILABLE); } _simulationInUse = false; } /* * Closing connection is that of a visitor in OBSERVE mode, remove * the visitor from the list of observers. */ else if (exitingVisitor.getCurrentRunMode() == GeppettoMessageInbound.VisitorRunMode.OBSERVING) { // User observing simulation is closing the connection if (_observers.contains(exitingVisitor)) { // Remove user from observers list _observers.remove(exitingVisitor); } // User observing simulation is closing the connection if (_queueUsers.contains(exitingVisitor)) { // Remove user from observers list _queueUsers.remove(exitingVisitor); } } } } /** * Requests JSONUtility class for a json object with a message to send to * the client * * @param requestID * * @param connection * - client to receive the message * @param type * - type of message to be send * @param string */ public void messageClient(String requestID, GeppettoMessageInbound connection, OUTBOUND_MESSAGE_TYPES type) { // get transport message to be sent to the client GeppettoTransportMessage transportMsg = TransportMessageFactory.getTransportMessage(requestID, type, null); String msg = new Gson().toJson(transportMsg); // Send the message to the client sendMessage(connection, msg); } /** * Requests JSONUtility class for a json object with simulation update to be * send to the client * * @param connection * - client to receive the simulation update * @param connection * - Type of udpate to be send * @param reloadCanvas * - update to be sent */ public void messageClient(String requestID, GeppettoMessageInbound connection, OUTBOUND_MESSAGE_TYPES type, String update) { // get transport message to be sent to the client GeppettoTransportMessage transportMsg = TransportMessageFactory.getTransportMessage(requestID, type, update); String msg = new Gson().toJson(transportMsg); sendMessage(connection, msg); } /** * Sends a message to a specific user. The id of the WebSocket connection is * used to contact the desired user. * * @param id * - ID of WebSocket connection that will be sent a message * @param msg * - The message the user will be receiving */ public void sendMessage(GeppettoMessageInbound visitor, String msg) { try { long startTime = System.currentTimeMillis(); CharBuffer buffer = CharBuffer.wrap(msg); visitor.getWsOutbound().writeTextMessage(buffer); String debug = ((long) System.currentTimeMillis() - startTime) + "ms were spent sending a message of " + msg.length() / 1024 + "KB to the client"; _logger.info(debug); } catch (IOException ignore) { _logger.error("Unable to communicate with client " + ignore.getMessage()); } } /** * Returns status of server simulation used * * @return */ public boolean isSimulationInUse() { return _simulationInUse; } public void getSimulationConfiguration(String requestID, String url, GeppettoMessageInbound visitor) { String simulationConfiguration; try { simulationConfiguration = visitor.getSimulationService().getSimulationConfig(new URL(url)); messageClient(requestID, visitor, OUTBOUND_MESSAGE_TYPES.SIMULATION_CONFIGURATION, simulationConfiguration); } catch (MalformedURLException e) { messageClient(requestID, visitor, OUTBOUND_MESSAGE_TYPES.ERROR_LOADING_SIMULATION_CONFIG, e.getMessage()); } catch (GeppettoInitializationException e) { messageClient(requestID, visitor, OUTBOUND_MESSAGE_TYPES.ERROR_LOADING_SIMULATION_CONFIG, e.getMessage()); } } public void getVersionNumber(String requestID, GeppettoMessageInbound visitor) { Properties prop = new Properties(); try { prop.load(GeppettoServletController.class.getResourceAsStream("/Geppetto.properties")); messageClient(requestID, visitor, OUTBOUND_MESSAGE_TYPES.GEPPETTO_VERSION, prop.getProperty("Geppetto.version")); } catch (IOException e) { _logger.error("Unable to read GEPPETTO.properties file"); } } public void getModelTree(String requestID, String aspectInstancePath, GeppettoMessageInbound visitor) { String modelTree = visitor.getSimulationService().getModelTree(aspectInstancePath); String update = "{\"aspectInstancePath\":" + '"' + aspectInstancePath + '"' + ",\"modelTree\":{" + modelTree + "}}"; // message the client with results this.messageClient(requestID, visitor, OUTBOUND_MESSAGE_TYPES.GET_MODEL_TREE, update); } /** * Sends parsed data from script to visitor client * * @param requestID * - Requested ID for process * @param url * - URL of script location * @param visitor * - Client doing the operation */ public void sendScriptData(String requestID, URL url, GeppettoMessageInbound visitor) { try { String line = null; StringBuilder sb = new StringBuilder(); BufferedReader br = new BufferedReader(new InputStreamReader(url.openStream())); while ((line = br.readLine()) != null) { sb.append(line + "\n"); } String script = sb.toString(); messageClient(requestID, visitor, OUTBOUND_MESSAGE_TYPES.RUN_SCRIPT, script); } catch (IOException e) { messageClient(requestID, visitor, OUTBOUND_MESSAGE_TYPES.ERROR_READING_SCRIPT); } } public static <T> T fromJSON(final TypeReference<T> type, String jsonPacket) throws GeppettoExecutionException { T data = null; try { data = new ObjectMapper().readValue(jsonPacket, type); } catch (Exception e) { throw new GeppettoExecutionException("could not de-serialize json"); } return data; } public void disableUser(String requestID, GeppettoMessageInbound visitor) { _connections.remove(visitor.getConnectionID()); postClosingConnectionCheck(visitor); } }