org.eclipse.osgi.internal.serviceregistry.ServiceObjectsImpl Maven / Gradle / Ivy
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/*******************************************************************************
* Copyright (c) 2013 IBM Corporation and others.
*
* This program and the accompanying materials
* are made available under the terms of the Eclipse Public License 2.0
* which accompanies this distribution, and is available at
* https://www.eclipse.org/legal/epl-2.0/
*
* SPDX-License-Identifier: EPL-2.0
*
* Contributors:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package org.eclipse.osgi.internal.serviceregistry;
import org.eclipse.osgi.internal.framework.BundleContextImpl;
import org.eclipse.osgi.internal.messages.Msg;
import org.osgi.framework.Bundle;
import org.osgi.framework.BundleContext;
import org.osgi.framework.Constants;
import org.osgi.framework.FrameworkEvent;
import org.osgi.framework.PrototypeServiceFactory;
import org.osgi.framework.ServiceException;
import org.osgi.framework.ServiceObjects;
import org.osgi.framework.ServiceReference;
import org.osgi.framework.ServiceRegistration;
/**
* ServiceObjects implementation.
*/
public class ServiceObjectsImpl implements ServiceObjects {
/** Service registration */
private final ServiceRegistrationImpl registration;
/** Reference to service */
private final ServiceReference reference;
/** BundleContext associated with this service use */
private final BundleContextImpl user;
/**
* Constructs a service objects encapsulating the service object.
*
* @param user bundle getting the service
* @param registration ServiceRegistration of the service
*/
ServiceObjectsImpl(BundleContextImpl user, ServiceRegistrationImpl registration) {
this.registration = registration;
this.reference = registration.getReference();
this.user = user;
}
/**
* Returns a service object for the {@link #getServiceReference() referenced}
* service.
*
*
* This {@code ServiceObjects} object can be used to obtain multiple service
* objects for the referenced service if the service has
* {@link Constants#SCOPE_PROTOTYPE prototype} scope. If the referenced service
* has {@link Constants#SCOPE_SINGLETON singleton} or
* {@link Constants#SCOPE_BUNDLE bundle} scope, this method behaves the same as
* calling the {@link BundleContext#getService(ServiceReference)} method for the
* referenced service. That is, only one, use-counted service object is
* available from this {@link ServiceObjects} object.
*
*
* This method will always return {@code null} when the referenced service has
* been unregistered.
*
*
* For a prototype scope service, the following steps are required to get the
* service object:
*
* - If the referenced service has been unregistered, {@code null} is
* returned.
* - The
* {@link PrototypeServiceFactory#getService(Bundle, ServiceRegistration)}
* method is called to create a service object for the caller.
* - If the service object returned by the {@code PrototypeServiceFactory}
* object is {@code null}, not an {@code instanceof} all the classes named when
* the service was registered or the {@code PrototypeServiceFactory} object
* throws an exception, {@code null} is returned and a Framework event of type
* {@link FrameworkEvent#ERROR} containing a {@link ServiceException} describing
* the error is fired.
* - The service object is returned.
*
*
* @return A service object for the referenced service or {@code null} if the
* service is not registered, the service object returned by a
* {@code ServiceFactory} does not implement the classes under which it
* was registered or the {@code ServiceFactory} threw an exception.
* @throws IllegalStateException If the BundleContext used to create this
* {@code ServiceObjects} object is no longer
* valid.
* @see #ungetService(Object)
*/
@Override
public S getService() {
user.checkValid();
return registration.getService(user, ServiceConsumer.prototypeConsumer);
}
/**
* Releases a service object for the {@link #getServiceReference() referenced}
* service.
*
*
* This {@code ServiceObjects} object can be used to obtain multiple service
* objects for the referenced service if the service has
* {@link Constants#SCOPE_PROTOTYPE prototype} scope. If the referenced service
* has {@link Constants#SCOPE_SINGLETON singleton} or
* {@link Constants#SCOPE_BUNDLE bundle} scope, this method behaves the same as
* calling the {@link BundleContext#ungetService(ServiceReference)} method for
* the referenced service. That is, only one, use-counted service object is
* available from this {@link ServiceObjects} object.
*
*
* For a prototype scope service, the following steps are required to release
* the service object:
*
* - If the referenced service has been unregistered, this method returns
* without doing anything.
* - The
* {@link PrototypeServiceFactory#ungetService(Bundle, ServiceRegistration, Object)}
* method is called to release the specified service object.
*
*
*
* The specified service object must no longer be used and all references to it
* should be destroyed after calling this method.
*
* @param service A service object previously provided by this
* {@code ServiceObjects} object.
* @throws IllegalStateException If the BundleContext used to create this
* {@code ServiceObjects} object is no longer
* valid.
* @throws IllegalArgumentException If the specified service was not provided by
* this {@code ServiceObjects} object.
* @see #getService()
*/
@Override
public void ungetService(S service) {
boolean removed = registration.ungetService(user, ServiceConsumer.prototypeConsumer, service);
if (!removed) {
if (registration.isUnregistered()) {
return;
}
if (user.isValid()) {
throw new IllegalArgumentException(Msg.SERVICE_OBJECTS_UNGET_ARGUMENT_EXCEPTION);
}
}
}
/**
* Returns the {@link ServiceReference} for the service associated with this
* {@code ServiceObjects} object.
*
* @return The {@link ServiceReference} for the service associated with this
* {@code ServiceObjects} object.
*/
@Override
public ServiceReference getServiceReference() {
return reference;
}
}