/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.isis.runtimes.dflt.runtime.persistence.objectfactory;
import java.lang.reflect.Modifier;
import org.apache.isis.core.metamodel.services.ServicesInjector;
import org.apache.isis.core.metamodel.spec.ObjectInstantiationException;
import org.apache.isis.core.metamodel.spec.SpecificationLoader;
import org.apache.isis.core.metamodel.spec.SpecificationLoaderAware;
import org.apache.isis.runtimes.dflt.runtime.system.context.IsisContext;
import org.apache.isis.runtimes.dflt.runtime.system.persistence.ObjectFactory;
import org.apache.isis.runtimes.dflt.runtime.system.persistence.PersistenceSession;
/**
* Abstract adapter for {@link ObjectFactory}.
*
* <p>
* Implementation note: rather than use the <tt>*Aware</tt> interfaces, we
* instead look up dependencies from the {@link IsisContext}. This is necessary,
* for the {@link PersistenceSession} at least, because class enhancers may hold
* a reference to the factory as part of the generated bytecode. Since the
* {@link PersistenceSession} could change over the lifetime of the instance (eg
* when using the {@link InMemoryObjectStore}), we must always look the
* {@link PersistenceSession} from the {@link IsisContext}. The same applies to
* the {@link ServicesInjector}.
*
* <p>
* In theory it would be possible to cache the {@link SpecificationLoader} and
* inject using {@link SpecificationLoaderAware}, but since we are already using
* the {@link IsisContext}, decided instead to use the same approach throughout.
*/
public abstract class ObjectFactoryAbstract implements ObjectFactory {
private final Mode mode;
public enum Mode {
/**
* Fail if no {@link ObjectAdapterPersistor} has been injected.
*/
STRICT,
/**
* Ignore if no {@link ObjectAdapterPersistor} has been injected
* (intended for testing only).
*/
RELAXED
}
public ObjectFactoryAbstract() {
this(Mode.STRICT);
}
public ObjectFactoryAbstract(final Mode mode) {
this.mode = mode;
}
@Override
public <T> T instantiate(final Class<T> cls) throws ObjectInstantiationException {
if (mode == Mode.STRICT && getServicesInjector() == null) {
throw new IllegalStateException("ServicesInjector has not been injected into ObjectFactory");
}
if (Modifier.isAbstract(cls.getModifiers())) {
throw new ObjectInstantiationException("Cannot create an instance of an abstract class: " + cls);
}
final T newInstance = doInstantiate(cls);
if (getServicesInjector() != null) {
getServicesInjector().injectDependencies(newInstance);
}
return newInstance;
}
// /////////////////////////////////////////////////////////////////
// open, close
// /////////////////////////////////////////////////////////////////
/**
* Default implementation does nothing.
*/
@Override
public void open() {
}
/**
* Default implementation does nothing.
*/
@Override
public void close() {
}
// /////////////////////////////////////////////////////////////////
// doInstantiate
// /////////////////////////////////////////////////////////////////
/**
* Hook method for subclasses to override.
*/
protected abstract <T> T doInstantiate(Class<T> cls) throws ObjectInstantiationException;
// /////////////////////////////////////////////////////////////////
// Dependencies (looked up from context)
// /////////////////////////////////////////////////////////////////
protected SpecificationLoader getSpecificationLoader() {
return IsisContext.getSpecificationLoader();
}
protected PersistenceSession getPersistenceSession() {
return IsisContext.getPersistenceSession();
}
protected ServicesInjector getServicesInjector() {
return getPersistenceSession().getServicesInjector();
}
}