Java tutorial
/* * Copyright (c) 2016 WSO2 Inc. (http://www.wso2.org) All Rights Reserved. * * 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.wso2.carbon.bpel.b4p.coordination; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.wso2.carbon.bpel.b4p.coordination.configuration.CoordinationConfiguration; import org.wso2.carbon.bpel.b4p.coordination.dao.HTCoordinationDAOConnectionFactory; import org.wso2.carbon.bpel.b4p.coordination.db.DatabaseConfigurationException; import org.wso2.carbon.bpel.b4p.coordination.db.DatabaseUtil; import org.wso2.carbon.bpel.b4p.coordination.event.listeners.EventListener; import org.wso2.carbon.bpel.b4p.internal.B4PContentHolder; import org.wso2.carbon.bpel.core.ode.integration.BPELServer; import org.wso2.carbon.bpel.core.ode.integration.BPELServerImpl; import java.util.concurrent.ExecutionException; import java.util.concurrent.ExecutorService; import java.util.concurrent.Executors; import java.util.concurrent.Future; import java.util.concurrent.ThreadFactory; import javax.transaction.TransactionManager; /** * CoordinationController, which initiate and execute humantask coordination. */ public class CoordinationController { private static final Log log = LogFactory.getLog(CoordinationController.class); /** * The transaction manager */ private TransactionManager tnxManager; private DatabaseUtil dbUtil; private HTCoordinationDAOConnectionFactory daoConnectionFactory; private CoordinationConfiguration configuration; private BPELServer bpelServer; private ExecutorService executorService; public CoordinationController() { configuration = CoordinationConfiguration.getInstance(); bpelServer = B4PContentHolder.getInstance().getBpelServer(); } /** * Initialization logic of B4P coordination service. * * @throws B4PCoordinationException : if coordination service initialization fails. */ public void init() throws B4PCoordinationException { if (configuration.isHumantaskCoordinationEnabled()) { log.info("Initialising B4P Coordination service"); initExecutorService(createThreadFactory()); initTransactionManager(); initDataSource(); initDao(); registerTerminationListener(); } } private void initExecutorService(ThreadFactory threadFactory) { executorService = Executors.newCachedThreadPool(threadFactory); } private void initTransactionManager() { if (log.isDebugEnabled()) { log.debug("Using BPEL server transaction manager"); } tnxManager = ((BPELServerImpl) bpelServer).getTransactionManager(); } /** * Initialize Database util class. * * @throws B4PCoordinationException */ private void initDataSource() throws B4PCoordinationException { if (log.isDebugEnabled()) { log.debug("Initialising B4P Coordination database"); } dbUtil = new DatabaseUtil(); dbUtil.setTransactionManager(tnxManager); try { dbUtil.start(); } catch (DatabaseConfigurationException e) { String errMsg = "B4P Coordination Database Initialization failed."; log.error(errMsg); throw new B4PCoordinationException(errMsg, e); } } private void initDao() throws B4PCoordinationException { if (log.isDebugEnabled()) { log.debug("Initialising B4P Coordination DAO Connection Factory"); } try { this.daoConnectionFactory = this.dbUtil.createDAOConnectionFactory(); } catch (DatabaseConfigurationException e) { String errMsg = "Error occurred during instantiating the DAO Connection Factory Class for B4P Coordination"; log.error(errMsg, e); throw new B4PCoordinationException(errMsg, e); } } /** * registering b4p EventListener to ODE engine */ private void registerTerminationListener() { if (log.isDebugEnabled()) { log.debug("Registering TerminationEvent listener"); } B4PContentHolder.getInstance().getBpelServer().registerEventListener(EventListener.class.getName()); } public HTCoordinationDAOConnectionFactory getDaoConnectionFactory() { return daoConnectionFactory; } private ThreadFactory createThreadFactory() { return new ThreadFactory() { private int threadNumber = 0; public Thread newThread(Runnable r) { threadNumber += 1; Thread t = new Thread(r, "B4PCoordination-" + threadNumber); t.setDaemon(true); return t; } }; } public void runTask(CoordinationTask task) { Future future = this.executorService.submit(task); try { future.get(); } catch (InterruptedException | ExecutionException e) { log.error("Error while executing coordination Task. ", e); } } }