This program demonstrates multithreaded producer-consumer pattern implemented in low-level Java native way.

The producer randomly creates commands on it's own which are being pushed to object-locked FIFO queue. 3 types of commands are implementing Command interface ( see the comments in the implementations ).

Consumer implements layered architecture (service -> DAO). In memory H2 database is accessed by DAO layer which solves transaction clashing by object locking too.

Not really necessary, but entity -> DTO is done by mapstruct used in service layer. Logback is being used for logging -- as it is most widely used logging facade with declarative way of configuration.

Testing is being performed by unit testing with help of JUnit 5.

For further discussion: for this to become more than demonstration application, producer, consumer and commons parts should be separated as maven modules. The testing is done on consumer side (service, mapper, DAO) and it does not cover the source as for enterprise application needs; however as a demonstration of Mockito framework I find this plenty enough.

The application action can be seen by running the ThreadingProducerConsumerTest::testProduceConsumeReporting test or by packaging it the standard maven way which will compile out two artefacts one of which you can run by standard java -jar produce-consume-34-mm-1.0-SNAPSHOT-jar-with-dependencies.jar way.