package org.apache.turbine.services.assemblerbroker;
/* ====================================================================
* The Apache Software License, Version 1.1
*
* Copyright (c) 2001 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution,
* if any, must include the following acknowledgment:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowledgment may appear in the software itself,
* if and wherever such third-party acknowledgments normally appear.
*
* 4. The names "Apache" and "Apache Software Foundation" and
* "Apache Turbine" must not be used to endorse or promote products
* derived from this software without prior written permission. For
* written permission, please contact apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache",
* "Apache Turbine", nor may "Apache" appear in their name, without
* prior written permission of the Apache Software Foundation.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*/
// JDK Stuff
import java.util.Vector;
import java.util.Hashtable;
// Turbine Stuff
import org.apache.turbine.modules.Assembler;
import org.apache.turbine.services.TurbineServices;
import org.apache.turbine.services.TurbineBaseService;
import org.apache.turbine.services.InitializationException;
import org.apache.turbine.services.assemblerbroker.util.AssemblerFactory;
import org.apache.turbine.services.resources.TurbineResources;
import org.apache.turbine.util.TurbineException;
/**
* TurbineAssemblerBrokerService allows assemblers (like screens,
* actions and layouts) to be loaded from one or more AssemblerFactory
* classes. AssemblerFactory classes are registered with this broker
* by adding them to the TurbineResources.properties file.
*
* @author <a href="mailto:leon@opticode.co.za">Leon Messerschmidt</a>
*/
public class TurbineAssemblerBrokerService
extends TurbineBaseService
implements AssemblerBrokerService
{
/** A structure that holds the registered AssemblerFactories*/
private Hashtable factories = null;
/**
* Get a list of AssemblerFactories of a certain type
*/
private Vector getFactoryGroup (String type)
{
if (!factories.containsKey (type))
{
factories.put (type, new Vector());
}
return (Vector)factories.get(type);
}
/**
* Utiltiy method to register all factories for a given
* type.
*/
private void registerFactories (String type)
throws TurbineException
{
String key = TurbineServices.SERVICE_PREFIX+
AssemblerBrokerService.SERVICE_NAME+
"."+
type;
String[] names = TurbineResources.getStringArray(key);
// Log.info ("Registering " + names.length + " " + type + " factories.");
for (int i=0; i<names.length; i++)
{
try
{
Object o = Class.forName ( names[i] ).newInstance();
registerFactory ( type, (AssemblerFactory)o );
}
// these must be passed to the VM
catch(ThreadDeath e)
{
throw e;
}
catch(OutOfMemoryError e)
{
throw e;
}
// when using Class.forName(), NoClassDefFoundErrors are likely
// to happen (missing jar files)
catch (Throwable t)
{
throw new TurbineException("Failed registering " + type + " factories", t);
}
}
}
/**
* Initializes the AssemblerBroker and loads the AssemblerFactory
* classes registerd in TurbineResources.Properties.
*/
public void init()
throws InitializationException
{
factories = new Hashtable();
try
{
registerFactories (AssemblerBrokerService.ACTION_TYPE);
registerFactories (AssemblerBrokerService.SCREEN_TYPE);
registerFactories (AssemblerBrokerService.NAVIGATION_TYPE);
registerFactories (AssemblerBrokerService.LAYOUT_TYPE);
registerFactories (AssemblerBrokerService.PAGE_TYPE);
registerFactories (AssemblerBrokerService.SCHEDULEDJOB_TYPE);
}
catch(TurbineException e)
{
throw new InitializationException("AssemblerBrokerService failed to initailize", e);
}
setInit(true);
}
/**
* Register a new AssemblerFactory under a certain type
*/
public void registerFactory( String type, AssemblerFactory factory )
{
getFactoryGroup(type).add (factory);
}
/**
* Attempt to retrieve an Assembler of a given type with
* a name. Cycle through all the registered AssemblerFactory
* classes of type and retrun the first non-null assembly
* found. If an assembly was not found return null.
*/
public Assembler getAssembler( String type, String name )
throws TurbineException
{
Vector facs = getFactoryGroup(type);
for (int i=0; i<facs.size(); i++)
{
AssemblerFactory fac = (AssemblerFactory)facs.get(i);
Assembler assembler = null;
try
{
assembler = fac.getAssembler (name);
}
catch (Exception e)
{
throw new TurbineException("Failed to find the "+type+" named "+name, e);
}
if (assembler != null)
return assembler;
}
return null;
}
}