Today we will finish (for now) our most recent iteration of our Shape Calculator component (or service, if you will). We have been on a long journey to this point. Once we are done, we will move onto:
I have been reading two great books, Object Thinking by David West and Clean Code by Robert C. Martin. In these two great books, the authors mention the phrase: “Everything is an object.” What caught my attention was that both express very different thoughts about this phrase. In his book, David West affirms that everything is an object and is a prerequisite if you want to be part of the object thinking culture. On the other hand, in his book, Robert C. Martin, says: “Mature programmers knows that the idea that everything is an object is a myth. Sometimes you really do want simple data structures with procedures operating on them”.
A bit of background of these two gentlemen. Robert C. Martin has written many books on software development, agile methodologies, and object oriented design and has founded Object Mentor, which is a company for mentoring and consulting on object oriented technologies. David West, Ph.D., is a consultant, educator and trainer in object oriented technologies. He founded and directed the Object Lab at the University of St. Thomas and cofounded the original Object Technology User Group.
Hopefully, you have been following along in this series of articles, and we are in the final stages of this iteration of a web-enabled Shape Calculator app. We have been pretending to enhance some in-house code that started out in your development team. I chose the Shape Calculator, but it could be anything.
Our first two rounds of the application were both command-line-interface and menu-driven.
As mentioned yesterday in Juergen’s blog post, the second milestone of Spring 5.0 introduced a new functional web framework. In this post, I will give more information about this framework.Example
We start with some excerpts from our sample application. Below is a reactive repository that exposes Person objects. It is quite similar to a traditional, non-reactive repository, except that it returns Flux<Person> where you would return a List<Person> traditionally, and Mono<Person> where you would return a Person. Mono<Void> is used as a completion signal: to indicate when the save has been completed. For more information on these Reactor types, refer to this blog post.
This blog presents instructions on how to quickly get started with Spring Boot Hello World with just one Java file and a Pom.xml.
Before getting to the files, make sure you have installed and configured the following:
In Part 1, we discussed the issue of resources not being cleaned up during shutdown and how to do this while dealing with the Root context and the Servlet context. If you want to actually try all this, check out the other article, as it has all the code.How to Release Resources
We have our ShapeCalcServletContextListener that implements ServletContextListener, and we know that it has references to the two resources we are concerned about at shutdown:
One of the “pleasures” of having your own business is dealing with accounting.
Now, to survive, I tried a few things like:
First of all, I’d like to thank everyone who created issues, raised Pull Requests, provided feedback or just asked questions on StackOverflow. Especial thanks for early adopters since the previous Milestone 1. With their help, we have improved and fixed some issues with runtime flow registration.
While programming in Scala, we often come across a term called a functor. A functor is an extremely simple, but powerful concept. In this blog, we'll discuss that in more detail.
Theoretically, a functor is a type of mapping between categories. Given two categories, A and B, a functor, F, maps the objects or entities of A to the objects or entities of B. We can simply call it a function of objects or entities.