A "tourism" receptive system based on gRPC (Google remote procedure call framework), implementing the observer GoF design pattern, and test driven development (TDD), written in Java.
Structured data can be serialized by using protocol buffers. gRPC exchanges those data between multiple services in different environments, in a microservices type architecture.
A project for personal learning and then teaching my students. Some test code from gRPC boilerplate - gRPC Java Basics and grpc Examples, testing clients and servers- has been included.
Based on the plot of the chapter 11th "Ricksy Business"" of Rick and Morty first season series.
Rick and Summer throw a party at home. Among the guests, there are teenagers, aliens, Gearhead, Squanchy, Birdpearson and Abradolf Lincler (a DNA mixture of Adolf Hitler and Abraham Lincoln).
When a guest enters the party he /she is processed in the receptive "tourist" system that Rick has developed ad hoc. The guest presents his /her credit card and the system charges:
- The reservation cost of a UFO to safely return home when the party is over.
- The cost of a welcome pack, a piece of Kalaxian Crystal, Rick's favourite amenities.
Rick is such a huge fan of the GoF design patterns book that he designs the system architecture in accordance with the observer pattern.
Both, the UFO reservation component and the kalaxian crystal dispenser component, observe the receptive component. Therefore, when a guest is processed by the receptive it charges automatically the guest credit card with the cost of both services. Of course, the system design is conformed with the SOLID Open Closed Principle (also respects Dependency Inversion Principle), so it is not necessary to modify the existing code to add and enable a new service component.
The figure shows the resulting UML class diagram:
As Rick find himself bored till the party starts, he decides to learn about gRPC - a "modern open source high performance RPC framework by Google"- and develops all the three components (UFOs park, crystal dispenser and payment services) running in separate microservices exchanging structured data in the form of protocol buffers.
The resulting "architecture" is this:
Rick has written the code with tons of fury and caffeine but, quoting himself "I programmed you to believe that", is the Test Driven Development (TDD) that saves the day. Paying the technical debt in a regular basis, is a matter of wubba lubba dub dub concern to him.
Mockito and harmcrest worth it.
Conventional commits are preferred too.
Clone this repo and move to the main folder:
$ cd ricksy-business-gRPCThen compile clients and servers:
$ ./gradlew clean build
$ ./gradle installDistFor focus on testing:
$ ./gradlew test$ ./build/install/grpc-ricksy-business/bin/payment-server
$ ./build/install/grpc-ricksy-business/bin/crystal-dispenser-server
$ ./build/install/grpc-ricksy-business/bin/ufos-park-serverMorty is joining the party (not without regret):
$ ./build/install/grpc-ricksy-business/bin/app Morty 1111111111111111Also, Rick friends are welcome too:
$ ./build/install/grpc-ricksy-business/bin/app Abradolf_Lincler 4916119711304546
$ ./build/install/grpc-ricksy-business/bin/app Squanchy 4444444444444444
$ ./build/install/grpc-ricksy-business/bin/app Gearhead 8888888888888888