Posts Tagged ‘SERLI’
[DevoxxBE2012] Weld-OSGi in Action
Mathieu Ancelin and Matthieu Clochard, software engineers at SERLI specializing in Java EE and modular systems, showcased the synergy between CDI, OSGi, and Weld in their Weld-OSGi framework during DevoxxBE2012. Mathieu, a member of the CDI 1.1 expert group and contributor to projects like GlassFish, collaborated with Matthieu, who focuses on OSGi integrations, to demonstrate how Weld-OSGi simplifies dynamic application assembly without added complexity.
They started with CDI basics, where dependency injection manages component lifecycles via annotations like @Inject. OSGi’s modularity, with bundles as deployment units and a dynamic service registry, complements this by allowing runtime changes. Weld-OSGi bridges them, enabling CDI beans to interact seamlessly with OSGi services.
A demo illustrated bootstrapping Weld-OSGi in an OSGi environment, registering bundles, and using extensions for event handling. They emphasized transparent service interactions, where CDI observes OSGi events for dynamic updates.
Mathieu and Matthieu highlighted Weld-OSGi’s role in making OSGi accessible, countering perceptions of its difficulty by leveraging CDI’s programming model.
Fundamentals of CDI and OSGi Integration
Mathieu explained CDI’s bean management, scopes, and qualifiers for precise injections. Matthieu detailed OSGi’s bundle lifecycle and service registry, where services publish and consume dynamically.
Weld-OSGi embeds CDI containers in OSGi, using extensions to observe bundle events and register services as beans. This allows injecting OSGi services into CDI components effortlessly.
Dynamic Features and Practical Demonstrations
They demonstrated service dynamism: publishing a service updates dependent beans automatically. Unpublishing triggers alternatives or errors, ensuring robustness.
Demos included hybrid applications where Java EE components interact with OSGi bundles via the registry, deploying parts dynamically without restarts.
Future Prospects and Community Engagement
Mathieu discussed ongoing work for hybrid servers like GlassFish, embedding Weld-OSGi for cleaner integrations. They referenced RFC 146, inspired by Weld-OSGi, for native CDI-OSGi support.
Encouraging trials, they pointed to GitHub repositories with examples and documentation, fostering feedback to evolve the framework.
Mathieu and Matthieu’s presentation illustrated Weld-OSGi’s potential to create fully dynamic modular applications, blending CDI’s elegance with OSGi’s power.