Java tutorial
/* * Copyright 2012-2014 Nikolay A. Viguro * <p/> * 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 * <p/> * http://www.apache.org/licenses/LICENSE-2.0 * <p/> * 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 ru.iris.events; import com.avaje.ebean.Ebean; import org.apache.commons.io.FileUtils; import org.apache.logging.log4j.LogManager; import org.apache.logging.log4j.Logger; import ru.iris.common.database.model.Event; import ru.iris.common.messaging.JsonEnvelope; import ru.iris.common.messaging.JsonMessaging; import ru.iris.common.messaging.JsonNotification; import ru.iris.common.messaging.model.command.CommandAdvertisement; import ru.iris.common.messaging.model.events.*; import ru.iris.common.modulestatus.Status; import javax.script.*; import java.io.File; import java.io.IOException; import java.util.HashMap; import java.util.List; import java.util.Map; import java.util.UUID; /** * Author: Nikolay A. Viguro * Date: 19.11.13 * Time: 11:25 */ public class EventsService { private final Logger LOGGER = LogManager.getLogger(EventsService.class.getName()); private final Compilable engine = (Compilable) new ScriptEngineManager().getEngineByName("nashorn"); private Map<String, CompiledScript> compiledScriptMap; private Map<String, CompiledScript> compiledCommandScriptMap = new HashMap<>(); private final JsonMessaging jsonMessaging = new JsonMessaging(UUID.randomUUID(), "events"); private final Logger scriptLogger = LogManager.getLogger(EventsService.class.getName()); private List<Event> events; public EventsService() { Status status = new Status("Events"); if (status.checkExist()) { status.running(); } else { status.addIntoDB("Events", "Service that listen for events and exec scripts as needed"); } try { events = Ebean.find(Event.class).findList(); // take pause to save/remove new entity try { Thread.sleep(500); } catch (InterruptedException e) { e.printStackTrace(); } // load all scripts, compile and put into map compiledScriptMap = loadAndCompile(events); // Pass jsonmessaging instance to js engine Bindings bindings = new SimpleBindings(); bindings.put("jsonMessaging", jsonMessaging); bindings.put("LOGGER", scriptLogger); // subscribe to events from db for (Event event : events) { jsonMessaging.subscribe(event.getSubject()); LOGGER.debug("Subscribe to subject: " + event.getSubject()); } // command launch jsonMessaging.subscribe("event.command"); // scripts jsonMessaging.subscribe("event.script.get"); jsonMessaging.subscribe("event.script.save"); jsonMessaging.subscribe("event.script.delete"); jsonMessaging.subscribe("event.script.list"); jsonMessaging.subscribe("event.reload"); jsonMessaging.setNotification(new JsonNotification() { @Override public void onNotification(JsonEnvelope envelope) { LOGGER.debug("Got envelope with subject: " + envelope.getSubject()); try { // Get script content if (envelope.getObject() instanceof EventGetScriptAdvertisement) { LOGGER.debug("Return JS script to: " + envelope.getReceiverInstance()); EventGetScriptAdvertisement advertisement = envelope.getObject(); File jsFile; if (advertisement.isCommand()) jsFile = new File("./scripts/command/" + advertisement.getName()); else jsFile = new File("./scripts/" + advertisement.getName()); jsonMessaging.response(envelope, new EventResponseGetScriptAdvertisement(FileUtils.readFileToString(jsFile))); } // Save new/existing script else if (envelope.getObject() instanceof EventResponseSaveScriptAdvertisement) { EventResponseSaveScriptAdvertisement advertisement = envelope.getObject(); LOGGER.debug("Request to save changes: " + advertisement.getName()); File jsFile; if (advertisement.isCommand()) jsFile = new File("./scripts/command/" + advertisement.getName()); else jsFile = new File("./scripts/" + advertisement.getName()); FileUtils.writeStringToFile(jsFile, advertisement.getBody()); LOGGER.info("Restart event service (reason: script change)"); reloadService(); } // Remove script else if (envelope.getObject() instanceof EventRemoveScriptAdvertisement) { EventRemoveScriptAdvertisement advertisement = envelope.getObject(); LOGGER.debug("Request to remove script: " + advertisement.getName()); File jsFile; if (advertisement.isCommand()) jsFile = new File("./scripts/command/" + advertisement.getName()); else jsFile = new File("./scripts/" + advertisement.getName()); FileUtils.forceDelete(jsFile); LOGGER.info("Restart event service (reason: script removed)"); reloadService(); } // List available scripts else if (envelope.getObject() instanceof EventListScriptsAdvertisement) { EventListScriptsAdvertisement advertisement = envelope.getObject(); File jsFile; if (advertisement.isCommand()) jsFile = new File("./scripts/command/"); else jsFile = new File("./scripts/"); EventResponseListScriptsAdvertisement response = new EventResponseListScriptsAdvertisement(); response.setScripts( (List<File>) FileUtils.listFiles(jsFile, new String[] { "js" }, false)); jsonMessaging.response(envelope, response); } // Check command and launch script else if (envelope.getObject() instanceof CommandAdvertisement) { CommandAdvertisement advertisement = envelope.getObject(); bindings.put("advertisement", envelope.getObject()); if (compiledCommandScriptMap.get(advertisement.getScript()) == null) { LOGGER.debug("Compile command script: " + advertisement.getScript()); File jsFile = new File("./scripts/command/" + advertisement.getScript()); CompiledScript compile = engine.compile(FileUtils.readFileToString(jsFile)); compiledCommandScriptMap.put(advertisement.getScript(), compile); LOGGER.debug("Launch compiled command script: " + advertisement.getScript()); compile.eval(bindings); } else { LOGGER.info("Launch compiled command script: " + advertisement.getScript()); compiledCommandScriptMap.get(advertisement.getScript()).eval(bindings); } } else if (envelope.getObject() instanceof EventChangesAdvertisement) { reloadService(); } else { for (Event event : events) { if (envelope.getSubject().equals(event.getSubject()) || wildCardMatch(event.getSubject(), envelope.getSubject())) { LOGGER.debug("Run compiled script: " + event.getScript()); try { bindings.put("advertisement", envelope.getObject()); CompiledScript script = compiledScriptMap.get(event.getScript()); if (script != null) script.eval(bindings); else LOGGER.error("Error! Script " + event.getScript() + " is NULL!"); } catch (ScriptException e) { LOGGER.error("Error in script scripts/command/" + event.getScript() + ": " + e.toString()); e.printStackTrace(); } } } } } catch (ScriptException | IOException e) { LOGGER.error("Error in script: " + e.toString()); e.printStackTrace(); } } }); jsonMessaging.start(); } catch (final RuntimeException t) { LOGGER.error("Error in Events!"); status.crashed(); t.printStackTrace(); } } private void reloadService() throws RuntimeException { LOGGER.info("Reload event service"); // unsubscribe current events for (Event event : events) { jsonMessaging.unsubscribe(event.getSubject()); LOGGER.debug("Unsubscribe from subject: " + event.getSubject()); } events = Ebean.find(Event.class).findList(); // subscribe to events from db for (Event event : events) { jsonMessaging.subscribe(event.getSubject()); LOGGER.debug("Subscribe from subject: " + event.getSubject()); } // take pause to save/remove new entity try { Thread.sleep(500); } catch (InterruptedException e) { e.printStackTrace(); } // load all scripts, compile and put into map compiledScriptMap = loadAndCompile(events); LOGGER.info("Reload event service done"); } private Map<String, CompiledScript> loadAndCompile(List<Event> events) throws RuntimeException { Map<String, CompiledScript> compiledScriptMap = new HashMap<>(); for (Event event : events) { File jsFile = new File("./scripts/" + event.getScript()); CompiledScript compile = null; try { compile = engine.compile(FileUtils.readFileToString(jsFile)); } catch (ScriptException | IOException e) { LOGGER.error("Compile error: " + e.getMessage()); } compiledScriptMap.put(event.getScript(), compile); } return compiledScriptMap; } private boolean wildCardMatch(String pattern, String text) throws RuntimeException { // add sentinel so don't need to worry about *'s at end of pattern text += '\0'; pattern += '\0'; int N = pattern.length(); boolean[] states = new boolean[N + 1]; boolean[] old = new boolean[N + 1]; old[0] = true; for (int i = 0; i < text.length(); i++) { char c = text.charAt(i); states = new boolean[N + 1]; // initialized to false for (int j = 0; j < N; j++) { char p = pattern.charAt(j); // hack to handle *'s that match 0 characters if (old[j] && (p == '*')) { old[j + 1] = true; } if (old[j] && (p == c)) { states[j + 1] = true; } if (old[j] && (p == '*')) { states[j] = true; } if (old[j] && (p == '*')) { states[j + 1] = true; } } old = states; } return states[N]; } public void stop() { jsonMessaging.close(); } }