/*
============================================================================
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 modifica-
tion, 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 "Jakarta", "Apache Avalon", "Avalon Framework" 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", 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 (INCLU-
DING, 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/>.
*/
package org.apache.avalon.meta.info.builder;
import java.io.InputStream;
import org.apache.avalon.excalibur.i18n.ResourceManager;
import org.apache.avalon.excalibur.i18n.Resources;
import org.apache.avalon.meta.info.Service;
/**
* A ServiceBuilder is responsible for building {@link Service}
* objects from Configuration objects.
*
* <p><b>UML</b></p>
* <p><image src="doc-files/ServiceBuilder.gif" border="0"/></p>
*
* @author <a href="mailto:dev@avalon.apache.org">Avalon Development Team</a>
* @version $Revision: 1.1.1.1 $ $Date: 2003/07/10 12:10:04 $
*/
public final class ServiceBuilder
{
private static final Resources REZ =
ResourceManager.getPackageResources( ServiceBuilder.class );
private final ServiceCreator m_xmlServiceCreator = createXMLServiceCreator();
private final ServiceCreator m_serialServiceCreator = new SerializedServiceCreator();
/**
* Create a {@link Service} object for specified Class.
*
* @param clazz The class of Component
* @return the created Service
* @throws Exception if an error occurs
*/
public Service build( final Class clazz )
throws Exception
{
return build( clazz.getName(), clazz.getClassLoader() );
}
/**
* Create a {@link Service} object for specified
* classname, in specified ClassLoader.
*
* @param classname The classname of Component
* @param classLoader the ClassLoader to load info from
* @return the created Service
* @throws Exception if an error occurs
*/
public Service build( final String classname,
final ClassLoader classLoader )
throws Exception
{
final Service info = buildFromSerDescriptor( classname, classLoader );
if( null != info )
{
return info;
}
else
{
return buildFromXMLDescriptor( classname, classLoader );
}
}
/**
* Build Service from the XML descriptor format.
*
* @param classname The classname of Component
* @param classLoader the ClassLoader to load info from
* @return the created Service
* @throws Exception if an error occurs
*/
private Service buildFromSerDescriptor( final String classname,
final ClassLoader classLoader )
throws Exception
{
final String xinfo =
classname.replace( '.', '/' ) + ".sinfo";
final InputStream inputStream =
classLoader.getResourceAsStream( xinfo );
if( null == inputStream )
{
return null;
}
return m_serialServiceCreator.createService( classname, inputStream );
}
/**
* Build Service from the XML descriptor format.
*
* @param classname The classname of Component
* @param classLoader the ClassLoader to load info from
* @return the created Service
* @throws Exception if an error occurs
*/
private Service buildFromXMLDescriptor( final String classname,
final ClassLoader classLoader )
throws Exception
{
//
// get the input stream for the .xservice resource
//
final String xservice =
classname.replace( '.', '/' ) + ".xservice";
final InputStream inputStream =
classLoader.getResourceAsStream( xservice );
if( null == inputStream )
{
final String message =
REZ.getString( "builder.missing-info.error",
classname );
throw new Exception( message );
}
//
// build the type
//
final ServiceCreator xmlServiceCreator = getXMLServiceCreator( classname );
return xmlServiceCreator.createService( classname, inputStream );
}
/**
* Utility to get xml info builder, else throw
* an exception if missing descriptor.
*
* @return the ServiceCreator
*/
private ServiceCreator getXMLServiceCreator( final String classname )
throws Exception
{
if( null != m_xmlServiceCreator )
{
return m_xmlServiceCreator;
}
else
{
final String message =
REZ.getString( "builder.missing-xml-creator.error",
classname );
throw new Exception( message );
}
}
/**
* Utility to get XMLServiceCreator if XML files are on
* ClassPath.
*
* @return the XML {@link ServiceCreator}
*/
private static ServiceCreator createXMLServiceCreator()
{
ServiceCreator xmlServiceCreator = null;
try
{
xmlServiceCreator = new XMLServiceCreator();
}
catch( final Exception e )
{
//Ignore it if ClassNot found due to no
//XML Classes on classpath
}
return xmlServiceCreator;
}
}