/*
* 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.instantiation;
import java.io.IOException;
import java.io.Serializable;
import java.io.StringWriter;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.dom4j.DocumentException;
import org.dom4j.DocumentHelper;
import org.dom4j.Element;
import org.dom4j.Node;
import org.dom4j.io.OutputFormat;
import org.dom4j.io.XMLWriter;
import org.jbpm.JbpmException;
import org.jbpm.graph.def.ProcessDefinition;
import org.jbpm.jpdl.xml.JpdlXmlReader;
import org.jbpm.jpdl.xml.Parsable;
import org.jbpm.util.ClassLoaderUtil;
import org.jbpm.util.EqualsUtil;
public class Delegation implements Parsable, Serializable {
private static final long serialVersionUID = 1L;
protected static Map instantiatorCache = new HashMap();
static {
instantiatorCache.put(null, new FieldInstantiator());
instantiatorCache.put("field", new FieldInstantiator());
instantiatorCache.put("bean", new BeanInstantiator());
instantiatorCache.put("constructor", new ConstructorInstantiator());
instantiatorCache.put("configuration-property", new ConfigurationPropertyInstantiator());
}
long id = 0;
protected String className = null;
protected String configuration = null;
protected String configType = null;
protected ProcessDefinition processDefinition = null;
transient Object instance = null;
public Delegation() {
}
public Delegation(Object instance) {
this.instance = instance;
}
public Delegation(String className) {
this.className = className;
}
public void read(Element delegateElement, JpdlXmlReader jpdlReader) {
processDefinition = jpdlReader.getProcessDefinition();
className = delegateElement.attributeValue("class");
if (className==null) {
jpdlReader.addWarning("no class specified in "+delegateElement.asXML());
}
configType = delegateElement.attributeValue("config-type");
if ( delegateElement.hasContent() ) {
try {
StringWriter stringWriter = new StringWriter();
// when parsing, it could be to store the config in the database, so we want to make the configuration compact
XMLWriter xmlWriter = new XMLWriter( stringWriter, OutputFormat.createCompactFormat() );
Iterator iter = delegateElement.content().iterator();
while (iter.hasNext()) {
Object node = iter.next();
xmlWriter.write( node );
}
xmlWriter.flush();
configuration = stringWriter.toString();
} catch (IOException e) {
jpdlReader.addWarning("io problem while parsing the configuration of "+delegateElement.asXML());
}
}
}
public void write(Element element) {
element.addAttribute("class", className);
element.addAttribute("config-type", configType);
String configuration = this.configuration;
if (configuration!=null) {
try {
Element actionElement = DocumentHelper.parseText( "<action>"+configuration+"</action>" ).getRootElement();
Iterator iter = new ArrayList( actionElement.content() ).iterator();
while (iter.hasNext()) {
Node node = (Node)iter.next();
node.setParent(null);
element.add( node );
}
} catch (DocumentException e) {
log.error("couldn't create dom-tree for action configuration '"+configuration+"'", e);
}
}
}
public Object getInstance() {
if (instance==null) {
instance = instantiate();
}
return instance;
}
public Object instantiate() {
Object newInstance = null;
// find the classloader to use
ClassLoader classLoader = ClassLoaderUtil.getProcessClassLoader(processDefinition);
// load the class that needs to be instantiated
Class clazz = null;
try {
clazz = classLoader.loadClass(className);
} catch (ClassNotFoundException e) {
log.error("couldn't load delegation class '"+className+"'", e);
}
Instantiator instantiator = null;
try {
// find the instantiator
instantiator = (Instantiator) instantiatorCache.get(configType);
if (instantiator == null) {
// load the instantiator class
Class instantiatorClass = classLoader.loadClass(configType);
// instantiate the instantiator with the default constructor
instantiator = (Instantiator) instantiatorClass.newInstance();
instantiatorCache.put(configType, instantiator);
}
} catch (Exception e) {
log.error(e);
throw new JbpmException("couldn't instantiate custom instantiator '" + configType + "'", e);
}
try {
// instantiate the object
newInstance = instantiator.instantiate(clazz, configuration);
} catch (RuntimeException e) {
log.error("couldn't instantiate delegation class '"+className+"'", e);
}
return newInstance;
}
// equals ///////////////////////////////////////////////////////////////////
// hack to support comparing hibernate proxies against the real objects
// since this always falls back to ==, we don't need to overwrite the hashcode
public boolean equals(Object o) {
return EqualsUtil.equals(this, o);
}
// getters and setters //////////////////////////////////////////////////////
public String getClassName() {
return className;
}
public void setClassName(String className) {
this.className = className;
}
public String getConfiguration() {
return configuration;
}
public void setConfiguration(String configuration) {
this.configuration = configuration;
}
public String getConfigType() {
return configType;
}
public void setConfigType(String instantiatorType) {
this.configType = instantiatorType;
}
public long getId() {
return id;
}
public void setId(long id) {
this.id = id;
}
public ProcessDefinition getProcessDefinition() {
return processDefinition;
}
public void setProcessDefinition(ProcessDefinition processDefinition) {
this.processDefinition = processDefinition;
}
private static final Log log = LogFactory.getLog(Delegation.class);
}