Java tutorial
/* * Copyright 2010-2011 the original author or authors. * * 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 com.googlecode.starflow.engine.support; import java.util.List; import java.util.concurrent.Callable; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.transaction.PlatformTransactionManager; import org.springframework.transaction.TransactionDefinition; import org.springframework.transaction.TransactionStatus; import org.springframework.transaction.support.DefaultTransactionDefinition; import com.googlecode.starflow.core.util.ApplicationContextHolder; import com.googlecode.starflow.engine.ExecutorService; import com.googlecode.starflow.engine.ProcessEngine; import com.googlecode.starflow.engine.ProcessEngineException; import com.googlecode.starflow.engine.core.Constants; import com.googlecode.starflow.engine.model.ProcessDefine; import com.googlecode.starflow.engine.model.ProcessInstance; import com.googlecode.starflow.engine.model.elements.EventElement; import com.googlecode.starflow.service.spi.IProcessTriggerEvent; /** * ?? * * @author libinsong1204@gmail.com * @version 1.0 */ public class TriggerProcessEventUtil { private static Logger logger = LoggerFactory.getLogger(TriggerProcessEventUtil.class); /** * ??? * * @param processEngine * @param processInstId * @param triggerEvents */ public static void beforeStart(ProcessEngine processEngine, ProcessDefine processDefine, ProcessInstance processInstance, List<EventElement> triggerEvents) { for (final EventElement eventXml : triggerEvents) { if (TriggerEventType.BEFORE_START_PROC.equals(eventXml.getEventType())) { action(processEngine, processDefine, processInstance, eventXml, new IAction() { @Override public void execute(ProcessDefine processDefine, ProcessInstance processInstance) { IProcessTriggerEvent processTriggerEvent = (IProcessTriggerEvent) ApplicationContextHolder .getBean(eventXml.getAction()); processTriggerEvent.beforeStart(processDefine.getProcessDefId()); } }); } } } /** * ??? * * @param processEngine * @param processInstId * @param triggerEvents */ public static void afterStart(ProcessEngine processEngine, ProcessDefine processDefine, ProcessInstance processInstance, List<EventElement> triggerEvents) { for (final EventElement eventXml : triggerEvents) { if (TriggerEventType.AFTER_START_PROC.equals(eventXml.getEventType())) { action(processEngine, processDefine, processInstance, eventXml, new IAction() { @Override public void execute(ProcessDefine processDefine, ProcessInstance processInstance) { IProcessTriggerEvent processTriggerEvent = (IProcessTriggerEvent) ApplicationContextHolder .getBean(eventXml.getAction()); processTriggerEvent.afterStart(processInstance.getProcessInstId()); } }); } } } /** * ??? * * @param processEngine * @param processInstId * @param triggerEvents */ public static void beforeComplete(ProcessEngine processEngine, ProcessDefine processDefine, ProcessInstance processInstance, List<EventElement> triggerEvents) { for (final EventElement eventXml : triggerEvents) { if (TriggerEventType.BEFORE_COMPLETE_PROC.equals(eventXml.getEventType())) { action(processEngine, processDefine, processInstance, eventXml, new IAction() { @Override public void execute(ProcessDefine processDefine, ProcessInstance processInstance) { IProcessTriggerEvent processTriggerEvent = (IProcessTriggerEvent) ApplicationContextHolder .getBean(eventXml.getAction()); processTriggerEvent.beforeComplete(processInstance.getProcessInstId()); } }); } } } /** * ??? * * @param processEngine * @param processInstId * @param triggerEvents */ public static void afterComplete(ProcessEngine processEngine, ProcessDefine processDefine, ProcessInstance processInstance, List<EventElement> triggerEvents) { for (final EventElement eventXml : triggerEvents) { if (TriggerEventType.AFTER_COMPLETE_PROC.equals(eventXml.getEventType())) { action(processEngine, processDefine, processInstance, eventXml, new IAction() { @Override public void execute(ProcessDefine processDefine, ProcessInstance processInstance) { IProcessTriggerEvent processTriggerEvent = (IProcessTriggerEvent) ApplicationContextHolder .getBean(eventXml.getAction()); processTriggerEvent.afterComplete(processInstance.getProcessInstId()); } }); } } } /** * ? * * ?suspend * ? * join??? * suspend??? * * @param processEngine * @param processInstId * @param eventXml * @param action */ private static void action(ProcessEngine processEngine, final ProcessDefine processDefine, final ProcessInstance processInstance, EventElement eventXml, final IAction action) { String invokePattern = eventXml.getInvokePattern(); final String transactionType = eventXml.getTransactionType(); ExecutorService executor = processEngine.getExecutorService(); if (Constants.ACT_AUTO_CALL_SYN.equalsIgnoreCase(invokePattern)) { //???????? try { executor.execute(new Callable<Object>() { public Object call() throws Exception { if (Constants.ACT_TRANSACTION_JOIN.equalsIgnoreCase(transactionType)) { action.execute(processDefine, processInstance); } else { executeLogicInNewTransaction(processDefine, processInstance, action); } return null; } }, invokePattern); } catch (Exception e) { handleException(e, eventXml); } } else { //suspend try { executor.execute(new Callable<Object>() { public Object call() throws Exception { executeLogicInNewTransaction(processDefine, processInstance, action); return null; } }, invokePattern); } catch (Exception e) { logger.error("Action", e); } } } /** * * @param e * @param eventXml */ private static void handleException(Exception e, EventElement eventXml) { String exceptionStrategy = eventXml.getExceptionStrategy(); if (Constants.ACT_EXCEPTIONSTRATEGY_ROLLBACK.equals(exceptionStrategy)) throw new ProcessEngineException("?", e); else { logger.error("?", e); } } /** * ? * * @param processInstId * @param action * @return */ private static void executeLogicInNewTransaction(ProcessDefine processDefine, ProcessInstance processInstance, IAction action) { PlatformTransactionManager txManager = ApplicationContextHolder.getBean(PlatformTransactionManager.class); DefaultTransactionDefinition definition = new DefaultTransactionDefinition(); definition.setPropagationBehavior(TransactionDefinition.PROPAGATION_REQUIRES_NEW); TransactionStatus status = txManager.getTransaction(definition); try { action.execute(processDefine, processInstance); txManager.commit(status); } catch (Exception e) { txManager.rollback(status); throw new ProcessEngineException("?", e); } } private static interface IAction { public void execute(ProcessDefine processDefine, ProcessInstance processInstance); } }