jbpmconfiguration.java

jBpm是一个灵活可扩展的工作流管理系统。作为jBpm运行时server输入的业务流程使用简单强大的语言表达并打包在流程档案中

/*
 * 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;

import java.io.ByteArrayInputStream;
import java.io.InputStream;
import java.io.Serializable;
import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.Map;
import java.util.Stack;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.jbpm.configuration.ObjectFactory;
import org.jbpm.configuration.ObjectFactoryImpl;
import org.jbpm.configuration.ObjectFactoryParser;
import org.jbpm.persistence.db.DbPersistenceServiceFactory;
import org.jbpm.svc.ServiceFactory;
import org.jbpm.svc.Services;
import org.jbpm.util.ClassLoaderUtil;

/**
 * configuration of one jBPM instance.
 * 
 * <p>During process execution, jBPM might need to use some services.  
 * A JbpmConfiguration contains the knowledge on how to create those services.
 * </p>
 * 
 * <p>A JbpmConfiguration is a thread safe object and serves as a factory for 
 * {@link org.jbpm.JbpmContext}s, which means one JbpmConfiguration 
 * can be used to create {@link org.jbpm.JbpmContext}s for all threads. 
 * The single JbpmConfiguration can be maintained in a static member or 
 * in the JNDI tree if that is available.
 * </p>
 * 
 * <p>A JbpmConfiguration can be obtained in following ways:
 * <ul>
 *   <li>from a resource (by default <code>jbpm.cfg.xml</code> is used):
 * <pre> JbpmConfiguration jbpmConfiguration = JbpmConfiguration.getInstance();
 * </pre>
 * or
 * <pre> String myXmlResource = "...";
 * JbpmConfiguration jbpmConfiguration = JbpmConfiguration.getInstance(myXmlResource);</pre> 
 *   </li>
 *   <li>from an XML string:
 * <pre> JbpmConfiguration jbpmConfiguration = JbpmConfiguration.parseXmlString(
 *   "<jbpm-configuration>" +
 *   ...
 *   "</jbpm-configuration>"
 * );
 * </pre>
 *   </li>
 *   <li>By specifying a custom implementation of an object factory.  This can be 
 *   used to specify a JbpmConfiguration in other bean-style notations such as 
 *   used by JBoss Microcontainer or Spring.
 * <pre> ObjectFactory of = new <i>MyCustomObjectFactory</i>();
 * JbpmConfiguration.Configs.setDefaultObjectFactory(of);
 * JbpmConfiguration jbpmConfiguration = JbpmConfiguration.getInstance();
 * </pre>
 *   </li>
 * </ul>
 * </p>
 * 
 * <p>JbpmConfigurations can be configured using a spring-like XML notation
 * (in relax ng compact notation):
 * </p>
 * 
 * <pre>
 * datatypes xs = "http://www.w3.org/2001/XMLSchema-datatypes"
 * 
 * start = element beans { element object* }
 * 
 * object = {
 *   jbpm-context |
 *   bean |
 *   ref |
 *   map |
 *   list |
 *   string |
 *   int |
 *   long |
 *   float |
 *   double |
 *   char |
 *   bool |
 *   true |
 *   false |
 *   null
 * }
 * 
 * jbpm-context = element jbpm-context {
 *   ( attribute name {xsd:string},
 *     service*,
 *     save-operations? 
 *   )
 * }
 * 
 * service = element service {
 *   ( attribute name {xsd:string},
 *     ( attribute factory {xsd:string} ) |
 *     ( factory )
 *   )
 * }
 * 
 * factory = element factory {
 *   ( bean |
 *     ref
 *   )
 * }
 * 
 * save-operations = element save-operations {
 *   ( save-operation* )
 * }
 * 
 * save-operation = element save-operation {
 *   ( ( attribute class {xsd:string} ) |
 *     ( bean |
 *       ref
 *     ) 
 *   )
 * }
 * 
 * bean = element bean {
 *   ( attribute ref-name {xsd:string} ) |
 *   ( attribute name {xsd:string}?,
 *     attribute class {xsd:string}?,
 *     attribute singleton { "true" | "false" }?,
 *     constructor*,
 *     field*,
 *     property*
 *   )
 * }
 * 
 * ref = element ref {
 *   ( attribute bean (xsd:string) )
 * }
 * 
 * constructor = element constructor {
 *   attribute class {xsd:string}?,
 *   ( attribute factory {xsd:string}, 
 *     attribute method {xsd:string}
 *   )?,
 *   parameter*
 * }
 * 
 * parameter = element parameter {
 *   attribute class {xsd:string},
 *   object
 * }
 * 
 * field = element field {
 *   attribute name {xsd:string},
 *   object
 * }
 * 
 * property = element property {
 *   ( attribute name {xsd:string} |
 *     attribute setter {xsd:string}
 *   ),
 *   object
 * }
 * 
 * map = element map {
 *   entry*
 * }
 * 
 * entry = element entry { 
 *   key, 
 *   value 
 * }
 * 
 * key = element key {
 *   object
 * }
 * 
 * value = element value {
 *   object
 * }
 * 
 * list = element list {
 *   object*
 * }
 * 
 * string = element string {xsd:string}
 * int    = element integer {xsd:integer}
 * long   = element long {xsd:long}
 * float  = element float {xsd:string}
 * double = element string {xsd:double}
 * char   = element char {xsd:character}
 * bool   = element bool { "true" | "false" }
 * true   = element true {}
 * false  = element false {}
 * null   = element null {}
 * </pre>
 * </p>
 * 
 * <p>
 * Other configuration properties
 * <table>
 *   <tr>
 *     <td>jbpm.msg.wait.timout</td><td></td>
 *   </tr>
 *   <tr>
 *     <td>jbpm.files.dir</td><td></td>
 *   </tr>
 *   <tr>
 *     <td>jbpm.types</td><td></td>
 *   </tr>
 * </table>
 * </p>
 */
public class JbpmConfiguration implements Serializable {
  
  private static final long serialVersionUID = 1L;

  static ObjectFactory defaultObjectFactory = null;
  static Map instances = new HashMap();
  
  /**
   * resets static members for test isolation.
   */
  static void reset() {
    defaultObjectFactory = null;
    instances = new HashMap();
  }

  ObjectFactory objectFactory = null;
  static ThreadLocal jbpmConfigurationsStacks = new ThreadLocal();
  ThreadLocal jbpmContextStacks = new ThreadLocal();

  public JbpmConfiguration(ObjectFactory objectFactory) {
    this.objectFactory = objectFactory;
  }
  public static JbpmConfiguration getInstance() {
    return getInstance(null);
  }
  public static JbpmConfiguration getInstance(String resource) {
    
    JbpmConfiguration instance = null;
    
    synchronized(instances) {
      if (resource==null) {
        resource = "jbpm.cfg.xml";
      }

      instance = (JbpmConfiguration) instances.get(resource);
      if (instance==null) {

        if (defaultObjectFactory!=null) {
          log.debug("creating jbpm configuration from given default object factory '"+defaultObjectFactory+"'");
          instance = new JbpmConfiguration(defaultObjectFactory);