org.osgi.service.component.runtime.ServiceComponentRuntime Maven / Gradle / Ivy
/*
* Copyright (c) OSGi Alliance (2013, 2017). 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.service.component.runtime;
import java.util.Collection;
import org.osgi.annotation.versioning.ProviderType;
import org.osgi.framework.Bundle;
import org.osgi.framework.Constants;
import org.osgi.service.component.ComponentContext;
import org.osgi.service.component.runtime.dto.ComponentConfigurationDTO;
import org.osgi.service.component.runtime.dto.ComponentDescriptionDTO;
import org.osgi.util.promise.Promise;
/**
* The {@code ServiceComponentRuntime} service represents the Declarative
* Services actor, known as Service Component Runtime (SCR), that manages the
* service components and their life cycle. The {@code ServiceComponentRuntime}
* service allows introspection of the components managed by Service Component
* Runtime.
*
* This service differentiates between a {@link ComponentDescriptionDTO} and a
* {@link ComponentConfigurationDTO}. A {@link ComponentDescriptionDTO} is a
* representation of a declared component description. A
* {@link ComponentConfigurationDTO} is a representation of an actual instance
* of a declared component description parameterized by component properties.
*
* This service must be registered with a {@link Constants#SERVICE_CHANGECOUNT}
* service property that must be updated each time the SCR DTOs available from
* this service change.
*
* Access to this service requires the
* {@code ServicePermission[ServiceComponentRuntime, GET]} permission. It is
* intended that only administrative bundles should be granted this permission
* to limit access to the potentially intrusive methods provided by this
* service.
*
* @ThreadSafe
* @since 1.3
* @author $Id: 5c261c47dfc8e80c6eee3b9b79c6f1c50c4464ce $
*/
@ProviderType
public interface ServiceComponentRuntime {
/**
* Returns the component descriptions declared by the specified active
* bundles.
*
*
* Only component descriptions from active bundles are returned. If the
* specified bundles have no declared components or are not active, an empty
* collection is returned.
*
* @param bundles The bundles whose declared component descriptions are to
* be returned. Specifying no bundles, or the equivalent of an empty
* {@code Bundle} array, will return the declared component
* descriptions from all active bundles.
* @return The declared component descriptions of the specified active
* {@code bundles}. An empty collection is returned if there are no
* component descriptions for the specified active bundles.
*/
Collection getComponentDescriptionDTOs(Bundle... bundles);
/**
* Returns the {@link ComponentDescriptionDTO} declared with the specified name
* by the specified bundle.
*
*
* Only component descriptions from active bundles are returned.
* {@code null} if no such component is declared by the given {@code bundle}
* or the bundle is not active.
*
* @param bundle The bundle declaring the component description. Must not be
* {@code null}.
* @param name The name of the component description. Must not be
* {@code null}.
* @return The declared component description or {@code null} if the
* specified bundle is not active or does not declare a component
* description with the specified name.
*/
ComponentDescriptionDTO getComponentDescriptionDTO(Bundle bundle, String name);
/**
* Returns the component configurations for the specified component
* description.
*
* @param description The component description. Must not be {@code null}.
* @return A collection containing a snapshot of the current component
* configurations for the specified component description. An empty
* collection is returned if there are none or if the provided
* component description does not belong to an active bundle.
*/
Collection getComponentConfigurationDTOs(ComponentDescriptionDTO description);
/**
* Returns whether the specified component description is currently enabled.
*
*
* The enabled state of a component description is initially set by the
* {@link ComponentDescriptionDTO#defaultEnabled enabled} attribute of the
* component description.
*
* @param description The component description. Must not be {@code null}.
* @return {@code true} if the specified component description is currently
* enabled. Otherwise, {@code false}.
* @see #enableComponent(ComponentDescriptionDTO)
* @see #disableComponent(ComponentDescriptionDTO)
* @see ComponentContext#disableComponent(String)
* @see ComponentContext#enableComponent(String)
*/
boolean isComponentEnabled(ComponentDescriptionDTO description);
/**
* Enables the specified component description.
*
* If the specified component description is currently enabled, this method
* has no effect.
*
* This method must return after changing the enabled state of the specified
* component description. Any actions that result from this, such as
* activating or deactivating a component configuration, must occur
* asynchronously to this method call.
*
* @param description The component description to enable. Must not be
* {@code null}.
* @return A promise that will be resolved when the actions that result from
* changing the enabled state of the specified component have
* completed. If the provided description does not belong to an
* active bundle, a failed promise is returned.
* @see #isComponentEnabled(ComponentDescriptionDTO)
*/
Promise enableComponent(ComponentDescriptionDTO description);
/**
* Disables the specified component description.
*
* If the specified component description is currently disabled, this method
* has no effect.
*
* This method must return after changing the enabled state of the specified
* component description. Any actions that result from this, such as
* activating or deactivating a component configuration, must occur
* asynchronously to this method call.
*
* @param description The component description to disable. Must not be
* {@code null}.
* @return A promise that will be resolved when the actions that result from
* changing the enabled state of the specified component have
* completed. If the provided description does not belong to an
* active bundle, a failed promise is returned.
* @see #isComponentEnabled(ComponentDescriptionDTO)
*/
Promise disableComponent(ComponentDescriptionDTO description);
}