org.osgi.framework.BundleActivator Maven / Gradle / Ivy
/*
* Copyright (c) OSGi Alliance (2000, 2013). 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;
/**
* Customizes the starting and stopping of a bundle.
*
* {@code BundleActivator} is an interface that may be implemented when a bundle
* is started or stopped. The Framework can create instances of a bundle's
* {@code BundleActivator} as required. If an instance's
* {@code BundleActivator.start} method executes successfully, it is guaranteed
* that the same instance's {@code BundleActivator.stop} method will be called
* when the bundle is to be stopped. The Framework must not concurrently call a
* {@code BundleActivator} object.
*
*
* {@code BundleActivator} is specified through the {@code Bundle-Activator}
* Manifest header. A bundle can only specify a single {@code BundleActivator}
* in the Manifest file. Fragment bundles must not have a
* {@code BundleActivator}. The form of the Manifest header is:
*
*
* {@code Bundle-Activator:} class-name
*
*
* where class-name is a fully qualified Java classname.
*
* The specified {@code BundleActivator} class must have a public constructor
* that takes no parameters so that a {@code BundleActivator} object can be
* created by {@code Class.newInstance()}.
*
* @NotThreadSafe
* @author $Id: a9d91a8ae13157f49a6a55b0c7f25b63b6bd00bd $
*/
@ConsumerType
public interface BundleActivator {
/**
* Called when this bundle is started so the Framework can perform the
* bundle-specific activities necessary to start this bundle. This method
* can be used to register services or to allocate any resources that this
* bundle needs.
*
*
* This method must complete and return to its caller in a timely manner.
*
* @param context The execution context of the bundle being started.
* @throws Exception If this method throws an exception, this bundle is
* marked as stopped and the Framework will remove this bundle's
* listeners, unregister all services registered by this bundle, and
* release all services used by this bundle.
*/
public void start(BundleContext context) throws Exception;
/**
* Called when this bundle is stopped so the Framework can perform the
* bundle-specific activities necessary to stop the bundle. In general, this
* method should undo the work that the {@code BundleActivator.start} method
* started. There should be no active threads that were started by this
* bundle when this bundle returns. A stopped bundle must not call any
* Framework objects.
*
*
* This method must complete and return to its caller in a timely manner.
*
* @param context The execution context of the bundle being stopped.
* @throws Exception If this method throws an exception, the bundle is still
* marked as stopped, and the Framework will remove the bundle's
* listeners, unregister all services registered by the bundle, and
* release all services used by the bundle.
*/
public void stop(BundleContext context) throws Exception;
}