What is BundleActivator?
BundleActivator is an interface that may be implemented when a bundle is started or stopped. The Framework can create instances of a bundle’s BundleActivator as required. If an instance’s BundleActivator. start method executes successfully, it is guaranteed that the same instance’s BundleActivator.
What is OSGi framework Java?
OSGi defines a dynamic module system for Java™. The OSGi service platform has a layered architecture, and is designed to run on various standard Java profiles. OSGi Applications deployed to WebSphere® Application Server run on an Enterprise Java profile that is provided as part of the server runtime environment.
What is the purpose of activator Java?
An Activator class is a Java class that controls the life cycle of a plug-in. This class triggers the actions on startup and shutdown, which makes an Activator the best place to allocate and release the resources that a plug-in uses.
What is activator Java in AEM?
Activator. java is a package in java that facilitates remote object activation.
Why do we need OSGi?
OSGi is a fast framework because it knows that which service will be loaded into OSGi environment thanks to pre-defined xml file. It reduces runtime cost thanks to lazy state. Service instance is created when they needed. Some bundle’s different version can be used by other bundle at the same time.
Who uses OSGi?
Who uses OSGi? 11 companies reportedly use OSGi in their tech stacks, including Liferay, Business Filemanager, and SYSTHEMIS AG.
What are services in OSGi?
What is a service? An OSGi service is a java object instance, registered into an OSGi framework with a set of properties. Any java object can be registered as a service, but typically it implements a well-known interface. The OSGi R3 specification, chapter 4.10 is highly recommended reading.
What is the point of OSGi?
OSGi is meant to solve common class loading issues that are seen in traditional Java EE environments; it is a set of specifications that are used in the creation of jars with extra manifest information to define dependencies and class loading behavior.
What is used to declare OSGi?
You then register your implementation using the declarative services component definition XML. In the component definition XML, you define that the InMemoryStorage class is an implementation of the StorageService . This allows the OSGi framework to handle the process of registering it as an OSGi service.
What is the default ranking of an OSGi service?
0
The default ranking is 0. A service with a ranking of Integer. MAX_VALUE is very likely to be returned as the default service, whereas a service with a ranking of Integer.
Is OSGi a Microservice?
OSGI is an application architecture, while microservices is a distributed systems concept. In my experience, microservices offer a number of benefits: Individual microservices are easy to deploy, test, and maintain. Microservices are language agnostic.
How does OSGi container work?
How does OSGi work? OSGi is a set of specifications that define a dynamic component system for Java. These specifications allow for a development model in which an application is composed of several components, and then packed into bundles. These components communicate locally and through the network via services.