REST microservices are a powerful tool for composing large-scale systems, and the standalone nature of a microservice helps to avoid it becoming part of a “big ball of mud” application. Given the power and success of microservices as inter-process modules, why stop there? OSGi has offered in-process microservices for nearly two decades, and uses them to great effect in modular applications.
The new OSGi JAX-RS whiteboard service allows dynamic OSGi services to be automatically exported as JAX-RS Resources, Filters or Applications. These “Microservice modules” can be easily shared or moved between frameworks, allowing you to benefit from a microservice structure that goes all the way down.