Axon Framework is an open source framework frequently used for building event-driven microservices on the JVM. Its architectural concepts are CQRS (Command Query Responsibility Segregation), DDD (domain-driven design), event sourcing, and location transparency.
The choice of using a framework for application development is somewhat controversial. You might have a look at this blog by Peter Kummins, which argues against the use of frameworks in general. More specific to the field in which my organization, Axon operates, father-of-CQRS Greg Young is known for advising “don’t write a CQRS framework,” and DDD authority Mathias Verraes recommended on Twitter not to use a framework for applications that have to last multiple years. This article by Tomas Petricek makes some other interesting points, clearly distinguishing between libraries and frameworks, and advocating for the use of libraries over frameworks.