/*
* This file is part of PFIXCORE.
*
* PFIXCORE 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 of the License, or
* (at your option) any later version.
*
* PFIXCORE 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 PFIXCORE; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
package de.schlund.pfixcore.generator;
import java.util.HashMap;
import de.schlund.pfixcore.util.FlyWeightChecker;
/**
* IHandlerFactory.java
*
*
* Created: Sat Oct 13 00:07:21 2001
*
* @author <a href="mailto:jtl@schlund.de">Jens Lautenbacher</a>
*
*
*/
public class IHandlerFactory {
private static HashMap<String, IHandler> knownhandlers = new HashMap<String, IHandler>();
private static HashMap<String, IHandler> wrapper2handlers = new HashMap<String, IHandler>();
// private static Logger LOG = Logger.getLogger(IHandlerFactory.class);
private static IHandlerFactory instance = new IHandlerFactory();
private IHandlerFactory() {
// do nothing.
}
/**
* <code>getInstance</code> returns the single Instance of a IHandlerFactory.
*
* @return an <code>IHandlerFactory</code> value
*/
public static IHandlerFactory getInstance() {
return instance;
}
/**
* <code>getIHandler</code> returns the IHandler for the given classname.
* (IHandlers are flyweights).
*
* @param classname a <code>String</code> value
* @return a <code>IHandler</code> value
*/
public IHandler getIHandler(String classname) {
synchronized (knownhandlers) {
IHandler retval = (IHandler) knownhandlers.get(classname);
if (retval == null) {
try {
Class<?> stateclass = Class.forName(classname);
retval = (IHandler) stateclass.newInstance();
if (!FlyWeightChecker.check(retval)) {
throw new IllegalStateException("You MUST NOT use non-static/non-final fields in flyweight class " + classname);
}
knownhandlers.put(classname, retval);
} catch (InstantiationException e) {
throw new IllegalStateException("unable to instantiate class [" + classname + "] :" + e.getMessage());
} catch (IllegalAccessException e) {
throw new IllegalStateException("unable access class [" + classname + "] :" + e.getMessage());
} catch (ClassNotFoundException e) {
throw new IllegalStateException("unable to find class [" + classname + "] :" + e.getMessage());
} catch (ClassCastException e) {
throw new IllegalStateException("class [" + classname + "] does not implement the interface IHandler. :" + e.getMessage());
}
}
// LOG.debug("Retval is: " + retval);
return retval;
}
}
public IHandler getIHandlerForWrapperClass(String classname) {
synchronized (wrapper2handlers) {
IHandler retval = wrapper2handlers.get(classname);
if (retval == null) {
try {
Class<?> stateclass = Class.forName(classname);
IWrapper wrapper = (IWrapper) stateclass.newInstance();
retval = wrapper.gimmeIHandler();
wrapper2handlers.put(classname, retval);
} catch (InstantiationException e) {
throw new IllegalStateException("unable to instantiate class [" + classname + "] :" + e.getMessage());
} catch (IllegalAccessException e) {
throw new IllegalStateException("unable access class [" + classname + "] :" + e.getMessage());
} catch (ClassNotFoundException e) {
throw new IllegalStateException("unable to find class [" + classname + "] :" + e.getMessage());
} catch (ClassCastException e) {
throw new IllegalStateException("class [" + classname + "] does not implement the interface IWrapper :"+ e.getMessage());
}
}
return retval;
}
}
}// IHandlerFactory
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