/*
* 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.jboss.util.state.xml;
import java.io.InputStream;
import java.net.URL;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import org.jboss.logging.Logger;
import org.jboss.util.state.State;
import org.jboss.util.state.StateMachine;
import org.jboss.util.state.Transition;
import org.jboss.util.xml.DOMUtils;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
/** Parse an xml representation of a state machine. A sample document is:
<state-machine description="JACC PolicyConfiguration States">
<state name="open">
<transition name="inService" target="open" />
<transition name="getContextID" target="open" />
<transition name="getPolicyConfiguration" target="open" />
<transition name="addToRole" target="open" />
<transition name="removeRole" target="open" />
<transition name="addToExcludedPolicy" target="open" />
<transition name="removeExcludedPolicy" target="open" />
<transition name="addToUncheckedPolicy" target="open" />
<transition name="removeUncheckedPolicy" target="open" />
<transition name="linkConfiguration" target="open" />
<transition name="commit" target="inService" />
<transition name="delete" target="deleted" />
</state>
<state name="inService">
<transition name="getPolicyConfiguration" target="open" />
<transition name="getContextID" target="inService" />
<transition name="inService" target="inService" />
<transition name="delete" target="deleted" />
</state>
<state name="deleted" isStartState="true">
<transition name="getPolicyConfiguration" target="open" />
<transition name="delete" target="deleted" />
<transition name="inService" target="deleted" />
<transition name="getContextID" target="deleted" />
</state>
</state-machine>
@author Scott.Stark@jboss.org
@author Dimitris.Andreadis@jboss.org
@version $Revision: 2787 $
*/
@SuppressWarnings("unchecked")
public class StateMachineParser
{
private static Logger log = Logger.getLogger(StateMachineParser.class);
public StateMachine parse(URL source) throws Exception
{
// parse the XML document into a DOM structure
InputStream in = source.openConnection().getInputStream();
Element root = DOMUtils.parse(in);
String description = root.getAttribute("description");
HashMap nameToStateMap = new HashMap();
HashMap nameToTransitionsMap = new HashMap();
HashSet states = new HashSet();
State startState = null;
// parse states
NodeList stateList = root.getChildNodes();
for (int i = 0; i < stateList.getLength(); i++)
{
Node stateNode = stateList.item(i);
if (stateNode.getNodeName().equals("state"))
{
Element stateElement = (Element)stateNode;
String stateName = stateElement.getAttribute("name");
State s = new State(stateName);
states.add(s);
nameToStateMap.put(stateName, s);
HashMap transitions = new HashMap();
// parse transitions
NodeList transitionList = stateElement.getChildNodes();
for (int j = 0; j < transitionList.getLength(); j++)
{
Node transitionNode = transitionList.item(j);
if (transitionNode.getNodeName().equals("transition"))
{
Element transitionElement = (Element)transitionNode;
String name = transitionElement.getAttribute("name");
String targetName = transitionElement.getAttribute("target");
transitions.put(name, targetName);
}
}
nameToTransitionsMap.put(stateName, transitions);
if (Boolean.valueOf(stateElement.getAttribute("isStartState")) == Boolean.TRUE)
startState = s;
}
}
// Resolve all transition targets
Iterator transitions = nameToTransitionsMap.keySet().iterator();
StringBuffer resolveFailed = new StringBuffer();
while (transitions.hasNext())
{
String stateName = (String)transitions.next();
State s = (State)nameToStateMap.get(stateName);
HashMap stateTransitions = (HashMap)nameToTransitionsMap.get(stateName);
Iterator it = stateTransitions.keySet().iterator();
while (it.hasNext())
{
String name = (String)it.next();
String targetName = (String)stateTransitions.get(name);
State target = (State)nameToStateMap.get(targetName);
if (target == null)
{
String msg = "Failed to resolve target state: " + targetName + " for transition: " + name;
resolveFailed.append(msg);
log.debug(msg);
}
Transition t = new Transition(name, target);
s.addTransition(t);
}
}
if (resolveFailed.length() > 0)
throw new Exception("Failed to resolve transition targets: " + resolveFailed);
StateMachine sm = new StateMachine(states, startState, description);
return sm;
}
}