/*
* The Apache Software License, Version 1.1
*
*
* Copyright (c) 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 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 "Axis" 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 (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/>.
*/
package org.apache.axis.configuration;
import java.lang.reflect.Method;
import org.apache.axis.EngineConfigurationFactory;
import org.apache.axis.components.logger.LogFactory;
import org.apache.axis.utils.JavaUtils;
import org.apache.commons.discovery.ResourceClassIterator;
import org.apache.commons.discovery.ResourceNameIterator;
import org.apache.commons.discovery.resource.ClassLoaders;
import org.apache.commons.discovery.resource.classes.DiscoverClasses;
import org.apache.commons.discovery.resource.names.DiscoverServiceNames;
import org.apache.commons.discovery.tools.ClassUtils;
import org.apache.commons.logging.Log;
/**
* This is a default implementation of EngineConfigurationFactory.
* It is user-overrideable by a system property without affecting
* the caller. If you decide to override it, use delegation if
* you want to inherit the behaviour of this class as using
* class extension will result in tight loops. That is, your
* class should implement EngineConfigurationFactory and keep
* an instance of this class in a member field and delegate
* methods to that instance when the default behaviour is
* required.
*
* @author Richard A. Sitze
*/
public class EngineConfigurationFactoryFinder
{
protected static Log log =
LogFactory.getLog(EngineConfigurationFactoryFinder.class.getName());
private static final Class mySpi = EngineConfigurationFactory.class;
private static final Class myFactory = EngineConfigurationFactoryFinder.class;
private static final Class[] newFactoryParamTypes =
new Class[] { Object.class };
private static final String requiredMethod =
"public static EngineConfigurationFactory newFactory(Object)";
private EngineConfigurationFactoryFinder() {
}
/**
* Create the default engine configuration and detect whether the user
* has overridden this with their own.
*
* The discovery mechanism will use the following logic:
*
* - discover all available EngineConfigurationFactories
* - find all META-INF/services/org.apache.axis.EngineConfigurationFactory
* files available through class loaders.
* - read files (see Discovery) to obtain implementation(s) of that
* interface
* - For each impl, call 'newFactory(Object param)'
* - Each impl should examine the 'param' and return a new factory ONLY
* - if it knows what to do with it
* (i.e. it knows what to do with the 'real' type)
* - it can find it's configuration information
* - Return first non-null factory found.
* - Try EngineConfigurationFactoryServlet.newFactory(obj)
* - Try EngineConfigurationFactoryDefault.newFactory(obj)
* - If zero found (all return null), throw exception
*
* ***
* This needs more work: System.properties, etc.
* Discovery will have more tools to help with that
* (in the manner of use below) in the near future.
* ***
*
*/
public static EngineConfigurationFactory newFactory(Object obj) {
/**
* recreate on each call is critical to gaining
* the right class loaders. Do not cache.
*/
Object[] params = new Object[] { obj };
/**
* Find and examine each service
*/
ClassLoaders loaders =
ClassLoaders.getAppLoaders(mySpi, myFactory, true);
ResourceNameIterator it =
new DiscoverServiceNames(loaders).findResourceNames(mySpi.getName());
ResourceClassIterator services =
new DiscoverClasses(loaders).findResourceClasses(it);
EngineConfigurationFactory factory = null;
while (factory == null && services.hasNext()) {
Class service = services.nextResourceClass().loadClass();
factory = newFactory(service, newFactoryParamTypes, params);
}
if (factory == null) {
try {
factory = EngineConfigurationFactoryServlet.newFactory(obj);
} catch (Exception e) {
log.warn(JavaUtils.getMessage("engineConfigInvokeNewFactory",
EngineConfigurationFactoryServlet.class.getName(),
requiredMethod), e);
}
if (factory == null) {
try {
// should NEVER return null.
factory = EngineConfigurationFactoryDefault.newFactory(obj);
} catch (Exception e) {
log.warn(JavaUtils.getMessage("engineConfigInvokeNewFactory",
EngineConfigurationFactoryDefault.class.getName(),
requiredMethod), e);
}
}
}
if (factory != null) {
log.debug(JavaUtils.getMessage("engineFactory", factory.getClass().getName()));
} else {
log.error(JavaUtils.getMessage("engineConfigFactoryMissing"));
// we should be throwing an exception here,
//
// but again, requires more refactoring than we want to swallow
// at this point in time. Ifthis DOES occur, it's a coding error:
// factory should NEVER be null.
// Testing will find this, as NullPointerExceptions will be generated
// elsewhere.
}
return factory;
}
public static EngineConfigurationFactory newFactory() {
return newFactory(null);
}
private static EngineConfigurationFactory newFactory(Class service,
Class[] paramTypes,
Object[] param) {
/**
* Verify that service implements:
* public static EngineConfigurationFactory newFactory(Object);
*/
Method method =
ClassUtils.findPublicStaticMethod(service,
EngineConfigurationFactory.class,
"newFactory",
paramTypes);
if (method == null) {
log.warn(JavaUtils.getMessage("engineConfigMissingNewFactory",
service.getName(),
requiredMethod));
} else {
try {
return (EngineConfigurationFactory)method.invoke(null, param);
} catch (Exception e) {
log.warn(JavaUtils.getMessage("engineConfigInvokeNewFactory",
service.getName(),
requiredMethod), e);
}
}
return null;
}
}