/*
* $Header: /home/cvs/jakarta-struts/src/share/org/apache/struts/tiles/definition/ReloadableDefinitionsFactory.java,v 1.5 2002/12/17 00:59:47 cedric Exp $
* $Revision: 1.5 $
* $Date: 2002/12/17 00:59:47 $
*
* ====================================================================
*
* The Apache Software License, Version 1.1
*
* Copyright (c) 1999-2002 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 acknowlegement:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowlegement may appear in the software itself,
* if and wherever such third-party acknowlegements normally appear.
*
* 4. The names "The Jakarta Project", "Struts", and "Apache Software
* Foundation" 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"
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* ====================================================================
*
* This software consists of voluntary contributions made by many
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* information on the Apache Software Foundation, please see
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*
*/
package org.apache.struts.tiles.definition;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Map;
import javax.servlet.ServletConfig;
import javax.servlet.ServletContext;
import javax.servlet.ServletRequest;
import javax.servlet.http.HttpServletRequest;
import org.apache.struts.tiles.ComponentDefinition;
import org.apache.struts.tiles.ComponentDefinitionsFactory;
import org.apache.struts.tiles.DefinitionsFactoryException;
import org.apache.struts.tiles.FactoryNotFoundException;
import org.apache.struts.tiles.xmlDefinition.I18nFactorySet;
import org.apache.struts.tiles.TilesUtil;
/**
* A reloadable factory.
* This factory is the main entrance to any factory implementation. It takes in
* charge real implementation instance, and allows reload of it by creating a new
* instance.
*
* @author Cedric Dumoulin
* @since 1.1
* @version $Revision: 1.5 $ $Date: 2002/12/17 00:59:47 $
*/
public class ReloadableDefinitionsFactory implements ComponentDefinitionsFactory
{
/** The real factory instance */
protected ComponentDefinitionsFactory factory;
/** Initialization parameters */
protected Map properties;
/** Name of init property carrying factory class name */
public static final String DEFINITIONS_FACTORY_CLASSNAME = "definitions-factory-class";
/**
* Constructor.
* Create a factory according to servlet settings.
* @throws DefinitionsFactoryException If factory creation fail.
*/
public ReloadableDefinitionsFactory( ServletContext servletContext, ServletConfig servletConfig )
throws DefinitionsFactoryException
{
properties = new ServletPropertiesMap( servletConfig );
factory = createFactory( servletContext, properties);
}
/**
* Constructor.
* Create a factory according to servlet settings.
* @throws DefinitionsFactoryException If factory creation fail.
*/
public ReloadableDefinitionsFactory( ServletContext servletContext, Map properties )
throws DefinitionsFactoryException
{
this.properties = properties;
factory = createFactory( servletContext, properties);
}
/**
* Create Definition factory from provided classname.
* If a factory class name is provided, a factory of this class is created. Otherwise,
* default factory is created.
* Factory must have a constructor taking ServletContext and Map as parameter.
* @param classname Class name of the factory to create.
* @param servletContext Servlet Context passed to newly created factory.
* @param properties Map of name/property passed to newly created factory.
* @return newly created factory.
* @throws DefinitionsFactoryException If an error occur while initializing factory
*/
public ComponentDefinitionsFactory createFactoryFromClassname(ServletContext servletContext, Map properties, String classname)
throws DefinitionsFactoryException
{
if( classname == null )
return createFactory( servletContext, properties );
// Try to create from classname
try
{
Class factoryClass = TilesUtil.applicationClass(classname);
ComponentDefinitionsFactory factory = (ComponentDefinitionsFactory)factoryClass.newInstance();
factory.initFactory( servletContext, properties);
return factory;
}
catch( ClassCastException ex )
{ // Bad classname
throw new DefinitionsFactoryException( "Error - createDefinitionsFactory : Factory class '"
+ classname +" must implements 'ComponentDefinitionsFactory'.", ex );
}
catch( ClassNotFoundException ex )
{ // Bad classname
throw new DefinitionsFactoryException( "Error - createDefinitionsFactory : Bad class name '"
+ classname +"'.", ex );
}
catch( InstantiationException ex )
{ // Bad constructor or error
throw new DefinitionsFactoryException( ex );
}
catch( IllegalAccessException ex )
{ //
throw new DefinitionsFactoryException( ex );
}
}
/**
* Create default Definition factory.
* Factory must have a constructor taking ServletContext and Map as parameter.
* In this implementation, default factory is of class I18nFactorySet
* @param servletContext Servlet Context passed to newly created factory.
* @param properties Map of name/property passed to newly created factory.
* @return newly created factory.
* @throws DefinitionsFactoryException If an error occur while initializing factory
*/
public ComponentDefinitionsFactory createDefaultFactory(ServletContext servletContext, Map properties)
throws DefinitionsFactoryException
{
ComponentDefinitionsFactory factory = new I18nFactorySet(servletContext, properties); ;
return factory;
}
/**
* Create Definition factory.
* Convenience method. ServletConfig is wrapped into a Map allowing retrieval
* of init parameters. Factory classname is also retrieved, as well as debug level.
* Finally, approriate createDefinitionsFactory() is called.
* @param servletContext Servlet Context passed to newly created factory.
* @param servletConfig Servlet config containing parameters to be passed to newly created factory.
*/
public ComponentDefinitionsFactory createFactory(ServletContext servletContext, Map properties)
throws DefinitionsFactoryException
{
String classname = (String)properties.get(DEFINITIONS_FACTORY_CLASSNAME);
if(classname!=null)
return createFactoryFromClassname( servletContext, properties, classname);
return new I18nFactorySet( servletContext, properties );
}
/**
* Get a definition by its name.
* Call appropriate method on underlying factory instance.
* Throw appropriate exception if definition or definition factory is not found.
* @param name Name of requested definition.
* @param request Current servelet request
* @param servletContext current servlet context
* @throws FactoryNotFoundException Can't find definition factory.
* @throws DefinitionsFactoryException General error in factory while getting definition.
* @throws NoSuchDefinitionException No definition found for specified name
*/
public ComponentDefinition getDefinition(String definitionName, ServletRequest request, ServletContext servletContext)
throws FactoryNotFoundException, DefinitionsFactoryException
{
return factory.getDefinition(definitionName, (HttpServletRequest)request, servletContext);
}
/**
* Reload underlying factory.
* Reload is done creating a new factory instance, and replacing old instance
* by the new one.
* @param request Current servelet request
* @param servletContext current servlet context
* @throws DefinitionsFactoryException If factory creation fail.
*/
public void reload(ServletContext servletContext)
throws DefinitionsFactoryException
{
ComponentDefinitionsFactory newInstance = createFactory( servletContext, properties);
factory = newInstance;
}
/**
* Get underlying factory instance.
*/
public ComponentDefinitionsFactory getFactory()
{
return factory;
}
/**
* Init factory.
* This method is required by interface ComponentDefinitionsFactory. It is
* not used in this implementation, as it manage itself underlying creation
* and initialization.
* @param servletContext Servlet Context passed to newly created factory.
* @param properties Map of name/property passed to newly created factory.
* Map can contains more properties than requested.
* @throws DefinitionsFactoryException An error occur during initialization.
*/
public void initFactory(ServletContext servletContext, Map properties) throws DefinitionsFactoryException
{ // do nothing
}
/**
* Get this object as a String
*/
public String toString()
{
return factory.toString();
}
/**
* Inner class.
* Wrapper for ServletContext init parameters.
* Object of this class is an hashmap containing parameters and values
* defined in the servlet config file (web.xml).
*/
class ServletPropertiesMap extends HashMap {
/**
* Constructor.
*/
ServletPropertiesMap( ServletConfig config )
{
// This implementation is very simple.
// It is possible to avoid creation of a new structure, but this need
// imply writing all Map interface.
Enumeration enum = config.getInitParameterNames();
while( enum.hasMoreElements() )
{
String key = (String)enum.nextElement();
put( key, config.getInitParameter( key ) );
}
}
} // end inner class
}