Java tutorial
/** * Copyright (c) 2013-2015 by The SeedStack authors. All rights reserved. * * This file is part of SeedStack, An enterprise-oriented full development stack. * * This Source Code Form is subject to the terms of the Mozilla Public * License, v. 2.0. If a copy of the MPL was not distributed with this * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ package org.seedstack.seed.scheduler.internal; import com.google.common.collect.ArrayListMultimap; import com.google.common.collect.Multimap; import org.seedstack.seed.core.api.SeedException; import org.seedstack.seed.scheduler.api.Scheduled; import org.seedstack.seed.scheduler.api.ScheduledTasks; import org.seedstack.seed.scheduler.api.Task; import org.seedstack.seed.scheduler.api.TaskListener; import io.nuun.kernel.api.plugin.InitState; import io.nuun.kernel.api.plugin.context.Context; import io.nuun.kernel.api.plugin.context.InitContext; import io.nuun.kernel.api.plugin.request.ClasspathScanRequest; import io.nuun.kernel.core.AbstractPlugin; import org.apache.commons.lang.StringUtils; import org.kametic.specifications.Specification; import org.quartz.Scheduler; import org.quartz.SchedulerException; import org.quartz.impl.StdSchedulerFactory; import javax.inject.Inject; import java.lang.reflect.ParameterizedType; import java.lang.reflect.Type; import java.util.Collection; import java.util.Map; /** * @author pierre.thirouin@ext.mpsa.com * Date: 08/01/14 */ public class SchedulerPlugin extends AbstractPlugin { private Specification<Class<?>> specificationForJobs; private Specification<Class<?>> specificationForJobListeners; private Collection<Class<?>> jobClasses; private Multimap<Class<? extends Task>, Class<? extends TaskListener>> jobListenerMap = ArrayListMultimap .create(); private Scheduler scheduler; @Inject static DelegateJobListener delegateJobListener; @Inject static GuiceTaskFactory guiceTaskFactory; @Inject static ScheduledTasks scheduledTasks; @Override public String name() { return "seed-scheduler-plugin"; } @Override public Collection<ClasspathScanRequest> classpathScanRequests() { specificationForJobs = classImplements(Task.class); specificationForJobListeners = classImplements(TaskListener.class); return classpathScanRequestBuilder().specification(specificationForJobs) .specification(specificationForJobListeners).build(); } @SuppressWarnings("unchecked") @Override public InitState init(InitContext initContext) { Map<Specification, Collection<Class<?>>> scannedTypesBySpecification = initContext .scannedTypesBySpecification(); // Associates - scan for nativeUnitModule jobClasses = scannedTypesBySpecification.get(specificationForJobs); Collection<Class<?>> listenerClasses = scannedTypesBySpecification.get(specificationForJobListeners); for (Class<?> listenerClass : listenerClasses) { if (TaskListener.class.isAssignableFrom(listenerClass)) { // Get the type of Job to listen Type typeVariable = getParametrizedTypeOfJobListener(listenerClass); if (typeVariable != null && Task.class.isAssignableFrom((Class<?>) typeVariable)) { // bind the Task to the listener jobListenerMap.put((Class<? extends Task>) typeVariable, (Class<? extends TaskListener>) listenerClass); } } } // Initialises the scheduler and adds jobs StdSchedulerFactory schedulerFactory = new StdSchedulerFactory(); try { this.scheduler = schedulerFactory.getScheduler(); } catch (Exception e) { throw SeedException.wrap(e, SchedulerErrorCode.SCHEDULER_ERROR); } return InitState.INITIALIZED; } /** * Return the type parameter of the TaskListener interface. * * @param listenerClass class to check * @return type which extends Task * @throws SeedException if no parameter type is present */ @SuppressWarnings("ThrowableResultOfMethodCallIgnored") private Type getParametrizedTypeOfJobListener(Class<?> listenerClass) { Type[] interfaces = listenerClass.getGenericInterfaces(); Type[] typeParameters = null; for (Type anInterface : interfaces) { // Checks if the class get parameters if (!(anInterface instanceof ParameterizedType)) { continue; } // Gets rawType to check if the interface is TaskListener Class interfaceClass = (Class) ((ParameterizedType) anInterface).getRawType(); if (TaskListener.class.isAssignableFrom(interfaceClass)) { typeParameters = ((ParameterizedType) anInterface).getActualTypeArguments(); break; } } if (typeParameters == null || typeParameters.length == 0) { throw SeedException.createNew(SchedulerErrorCode.MISSING_TYPE_PARAMETER).put("class", listenerClass); } return typeParameters[0]; } @Override public void start(Context context) { super.start(context); try { // Configure scheduler scheduler.setJobFactory(guiceTaskFactory); scheduler.getListenerManager().addJobListener(delegateJobListener); // Schedule declarative jobs (@Scheduled) scheduleJobs(); // Start scheduler scheduler.start(); } catch (Exception e) { throw SeedException.wrap(e, SchedulerErrorCode.SCHEDULER_FAILED_TO_START); } } /** * Schedules {@code Jobs} which have a Scheduled annotation with cron expression. * * @throws SeedException when the {@code Job} can't be schedule. */ private void scheduleJobs() { try { for (Class<?> candidateClass : jobClasses) { if (Task.class.isAssignableFrom(candidateClass)) { Scheduled annotation = candidateClass.getAnnotation(Scheduled.class); if (annotation != null && StringUtils.isNotBlank(annotation.value())) { Class<? extends Task> taskClass = (Class<? extends Task>) candidateClass; scheduledTasks.scheduledTask(taskClass).schedule(); } } } } catch (Exception e) { throw SeedException.wrap(e, SchedulerErrorCode.SCHEDULER_ERROR); } } @Override public void stop() { try { if (this.scheduler != null) { this.scheduler.shutdown(); } } catch (SchedulerException e) { throw SeedException.wrap(e, SchedulerErrorCode.SCHEDULER_FAILED_TO_SHUTDOWN); } super.stop(); } @Override public Object nativeUnitModule() { return new SchedulerModule(jobClasses, scheduler, jobListenerMap); } }