/* * Copyright (c) OSGi Alliance (2012, 2014). All Rights Reserved. * * Licensed 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.osgi.framework; import org.osgi.annotation.versioning.ConsumerType; /** * A factory for {@link Constants#SCOPE_PROTOTYPE prototype scope} services. The * factory can provide multiple, customized service objects in the OSGi * environment. * *
* When registering a service, a {@code PrototypeServiceFactory} object can be * used instead of a service object, so that the bundle developer can create a * customized service object for each caller that is using the service. * *
* When a caller uses a {@link ServiceObjects} to * {@link ServiceObjects#getService() request} a service object, the framework * calls the {@link #getService(Bundle, ServiceRegistration) getService} method * to return a service object customized for the requesting caller. The caller * can {@link ServiceObjects#ungetService(Object) release} the returned service * object and the framework will call the * {@link #ungetService(Bundle, ServiceRegistration, Object) ungetService} * method with the service object. * *
* When a bundle uses the {@link BundleContext#getService(ServiceReference)} * method to obtain a service object, the framework must act as if the service * has {@link Constants#SCOPE_BUNDLE bundle scope}. That is, the framework will * call the {@link #getService(Bundle, ServiceRegistration) getService} method * to obtain a bundle-scoped service object which will be cached and have a use * count. See {@link ServiceFactory}. * *
* A bundle can use both {@link ServiceObjects} and * {@link BundleContext#getService(ServiceReference)} to obtain a service object * for a service. {@link ServiceObjects#getService()} will always return a * service object provided by a call to * {@link #getService(Bundle, ServiceRegistration)} and * {@link BundleContext#getService(ServiceReference)} will always return the * bundle-scoped service object. * *
* {@code PrototypeServiceFactory} objects are only used by the Framework and
* are not made available to other bundles in the OSGi environment. The
* Framework may concurrently call a {@code PrototypeServiceFactory}.
*
* @param Type of Service
* @see BundleContext#getServiceObjects(ServiceReference)
* @see ServiceObjects
* @ThreadSafe
* @since 1.8
* @author $Id$
*/
@ConsumerType
public interface PrototypeServiceFactory extends ServiceFactory {
/**
* Returns a service object for a caller.
*
*
* The Framework invokes this method for each caller requesting a service * object using {@link ServiceObjects#getService()}. The factory can then * return a customized service object for the caller. * *
* The Framework must check that the returned service object is valid. If
* the returned service object is {@code null} or is not an
* {@code instanceof} all the classes named when the service was registered,
* a framework event of type {@link FrameworkEvent#ERROR} is fired
* containing a service exception of type
* {@link ServiceException#FACTORY_ERROR} and {@code null} is returned to
* the caller. If this method throws an exception, a framework event of type
* {@link FrameworkEvent#ERROR} is fired containing a service exception of
* type {@link ServiceException#FACTORY_EXCEPTION} with the thrown exception
* as the cause and {@code null} is returned to the caller.
*
* @param bundle The bundle requesting the service.
* @param registration The {@code ServiceRegistration} object for the
* requested service.
* @return A service object that must be an instance of all
* the classes named when the service was registered.
* @see ServiceObjects#getService()
*/
public S getService(Bundle bundle, ServiceRegistration registration);
/**
* Releases a service object customized for a caller.
*
*
* The Framework invokes this method when a service has been released by a * bundle such as by calling {@link ServiceObjects#ungetService(Object)}. * The service object may then be destroyed. * *
* If this method throws an exception, a framework event of type
* {@link FrameworkEvent#ERROR} is fired containing a service exception of
* type {@link ServiceException#FACTORY_EXCEPTION} with the thrown exception
* as the cause.
*
* @param bundle The bundle releasing the service.
* @param registration The {@code ServiceRegistration} object for the
* service being released.
* @param service The service object returned by a previous call to the
* {@link #getService(Bundle, ServiceRegistration) getService}
* method.
* @see ServiceObjects#ungetService(Object)
*/
public void ungetService(Bundle bundle, ServiceRegistration registration, S service);
}