Describe how the OSGi service registry functions and how it can be used in a project.
The OSGi service registry is a dynamic directory of services available within an OSGi environment. It allows bundles to detect the addition, modification, or removal of services and adapt accordingly. This dynamism enables loose coupling between components, enhancing modularity.
In a project, the registry can be used for inter-bundle communication. A bundle providing a service registers it with the registry. Other bundles needing that service query the registry and bind to the service if found. If multiple instances of a service exist, the registry uses a ranking system to determine which one to return.
Service events are broadcasted by the registry when services are registered, modified, or unregistered. Bundles can listen for these events and react appropriately, ensuring they always use the most suitable service instance.
