Java tutorial
/* * JBoss, Home of Professional Open Source * Copyright 2005, JBoss Inc., and individual contributors as indicated * by the @authors tag. See the copyright.txt in the distribution for a * full listing of individual contributors. * * This is free software; you can redistribute it and/or modify it * under the terms of the GNU Lesser General Public License as * published by the Free Software Foundation; either version 2.1 of * the License, or (at your option) any later version. * * This software is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this software; if not, write to the Free * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA * 02110-1301 USA, or see the FSF site: http://www.fsf.org. */ package org.jbpm.graph.exe; import java.util.ArrayList; import java.util.List; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.jbpm.JbpmContext; import org.jbpm.context.exe.ContextInstance; import org.jbpm.graph.def.Action; import org.jbpm.graph.def.Event; import org.jbpm.graph.def.GraphElement; import org.jbpm.graph.def.Node; import org.jbpm.graph.def.ProcessDefinition; import org.jbpm.graph.def.Transition; import org.jbpm.module.def.ModuleDefinition; import org.jbpm.module.exe.ModuleInstance; import org.jbpm.job.Timer; import org.jbpm.taskmgmt.def.Task; import org.jbpm.taskmgmt.exe.TaskInstance; import org.jbpm.taskmgmt.exe.TaskMgmtInstance; public class ExecutionContext { protected Token token; protected Event event; protected GraphElement eventSource; protected Action action; protected Throwable exception; protected Transition transition; protected Node transitionSource; protected Task task; protected Timer timer; protected TaskInstance taskInstance; protected ProcessInstance subProcessInstance; public ExecutionContext(Token token) { this.token = token; this.subProcessInstance = token.getSubProcessInstance(); } public ExecutionContext(ExecutionContext other) { this.token = other.token; this.event = other.event; this.action = other.action; } public Node getNode() { return token.getNode(); } public ProcessDefinition getProcessDefinition() { ProcessInstance processInstance = getProcessInstance(); return (processInstance != null ? processInstance.getProcessDefinition() : null); } public void setAction(Action action) { this.action = action; if (action != null) this.event = action.getEvent(); } public ProcessInstance getProcessInstance() { return token.getProcessInstance(); } public String toString() { return "ExecutionContext(" + token.getName() + ')'; } // convenience methods ////////////////////////////////////////////////////// /** * set a process variable. */ public void setVariable(String name, Object value) { if (taskInstance != null) { taskInstance.setVariable(name, value); } else { getContextInstance().setVariable(name, value, token); } } /** * get a process variable. */ public Object getVariable(String name) { return taskInstance != null ? taskInstance.getVariable(name) : getContextInstance().getVariable(name, token); } /** * leave this node over the default transition. This method is only available * on node actions. Not on actions that are executed on events. Actions on * events cannot change the flow of execution. */ public void leaveNode() { getNode().leave(this); } /** * leave this node over the given transition. This method is only available on * node actions. Not on actions that are executed on events. Actions on events * cannot change the flow of execution. */ public void leaveNode(String transitionName) { getNode().leave(this, transitionName); } /** * leave this node over the given transition. This method is only available on * node actions. Not on actions that are executed on events. Actions on events * cannot change the flow of execution. */ public void leaveNode(Transition transition) { getNode().leave(this, transition); } public ModuleDefinition getDefinition(Class clazz) { return getProcessDefinition().getDefinition(clazz); } public ModuleInstance getInstance(Class clazz) { if (token != null) { ProcessInstance processInstance = token.getProcessInstance(); if (processInstance != null) return processInstance.getInstance(clazz); } return null; } public ContextInstance getContextInstance() { return (ContextInstance) getInstance(ContextInstance.class); } public TaskMgmtInstance getTaskMgmtInstance() { return (TaskMgmtInstance) getInstance(TaskMgmtInstance.class); } public JbpmContext getJbpmContext() { return JbpmContext.getCurrentJbpmContext(); } // getters and setters ////////////////////////////////////////////////////// public void setTaskInstance(TaskInstance taskInstance) { this.taskInstance = taskInstance; this.task = taskInstance != null ? taskInstance.getTask() : null; } public Token getToken() { return token; } public Action getAction() { return action; } public Event getEvent() { return event; } public void setEvent(Event event) { this.event = event; } public Throwable getException() { return exception; } public void setException(Throwable exception) { this.exception = exception; } public Transition getTransition() { return transition; } public void setTransition(Transition transition) { this.transition = transition; } public Node getTransitionSource() { return transitionSource; } public void setTransitionSource(Node transitionSource) { this.transitionSource = transitionSource; } public GraphElement getEventSource() { return eventSource; } public void setEventSource(GraphElement eventSource) { this.eventSource = eventSource; } public Task getTask() { return task; } public void setTask(Task task) { this.task = task; } public TaskInstance getTaskInstance() { return taskInstance; } public ProcessInstance getSubProcessInstance() { return subProcessInstance; } public void setSubProcessInstance(ProcessInstance subProcessInstance) { this.subProcessInstance = subProcessInstance; } public Timer getTimer() { return timer; } public void setTimer(Timer timer) { this.timer = timer; } // thread local execution context static ThreadLocal threadLocalContextStack = new ThreadLocal() { protected Object initialValue() { return new ArrayList(); } }; static List getContextStack() { return (List) threadLocalContextStack.get(); } public static void pushCurrentContext(ExecutionContext executionContext) { getContextStack().add(executionContext); } public static void popCurrentContext(ExecutionContext executionContext) { List stack = getContextStack(); int index = stack.lastIndexOf(executionContext); if (index == -1) { log.warn(executionContext + " was not found in thread-local stack;" + " do not access ExecutionContext instances from multiple threads"); } else { if (index < stack.size() - 1) { log.warn(executionContext + " was not popped in reverse push order;" + " make sure you pop every context you push"); } // remove execution context from stack, no matter what stack.remove(index); } } public static ExecutionContext currentExecutionContext() { List stack = getContextStack(); return stack.isEmpty() ? null : (ExecutionContext) stack.get(stack.size() - 1); } private static final Log log = LogFactory.getLog(ExecutionContext.class); }