nodetypes.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.graph.node;

import java.io.InputStream;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.jbpm.JbpmConfiguration;
import org.jbpm.util.ClassLoaderUtil;
import org.jbpm.util.XmlUtil;
import org.w3c.dom.Element;

public class NodeTypes {

  public static Set getNodeTypes() {
    return nodeNames.keySet();
  }
  
  public static Set getNodeNames() {
    return nodeTypes.keySet();
  }
  
  public static Class getNodeType(String name) {
    return (Class) nodeTypes.get(name);
  }
  
  public static String getNodeName(Class type) {
    return (String) nodeNames.get(type);
  }
  
  private static final Log log = LogFactory.getLog(NodeTypes.class);

  static Map nodeTypes = initialiseNodeTypes();
  static Map nodeNames = createInverseMapping(nodeTypes);
  
  static Map initialiseNodeTypes() {
    Map types = new HashMap();

    String resource = JbpmConfiguration.Configs.getString("resource.node.types");
    InputStream actionTypesStream = ClassLoaderUtil.getStream(resource);
    Element nodeTypesElement = XmlUtil.parseXmlInputStream(actionTypesStream).getDocumentElement();
    Iterator nodeTypeIterator = XmlUtil.elementIterator(nodeTypesElement, "node-type");
    while(nodeTypeIterator.hasNext()) {
      Element nodeTypeElement = (Element) nodeTypeIterator.next();

      String elementTag = nodeTypeElement.getAttribute("element");
      String className = nodeTypeElement.getAttribute("class");
      try {
        Class nodeClass = ClassLoaderUtil.getClassLoader().loadClass(className);
        types.put(elementTag, nodeClass);
        
      } catch (Exception exception) {
        // NOTE that Error's are not caught because that might halt the JVM and mask the original Error.
        if (!"org.jboss.seam.jbpm.Page".equals(className)) {
          log.debug("node '"+elementTag+"' will not be available. class '"+className+"' couldn't be loaded");
        }
      }
    }

    return types; 
  }

  public static Map createInverseMapping(Map map) {
    Map names = new HashMap();
    Iterator iter = map.entrySet().iterator();
    while (iter.hasNext()) {
      Map.Entry entry = (Map.Entry) iter.next();
      names.put(entry.getValue(), entry.getKey());
    }
    return names;
  }
}