This post will have a lot of code and Java at that, so warning has been given. I happened on this little gem in the Java standard library that allows you to make a nice asynchronous model of execution with some guidance. Only the thing missing from the documentation of the Java standard library, in contrast to the one provided by Python, are examples on how to use this one. There is an example on the main page of the package. So this is my attempt at creating the implementation of these interfaces and hooking them up together based on the wordings in the documentation.

This post is about why you want immutable objects and how to achieve that in various ways. I specify the language as Java this time because I want to showcase the Quarkus framework. This pattern can be used in any language and framework combination using the tools available in that language of course.

To be honest I have no idea what you can do with the following pattern and if it is good at all. It just a thought I had and it felt like there was something there, so I decided to write it down. Hopefully you can use the following pattern for something.

This idea comes from JavaScript when there were no classes yet as there are now in ES6. You would write something like this:

So this will hopefully convey the message on how to model your code in order to have things done in a nicer way.

I started a project recently using Spring WebFlux which is based upon Project Reactor. I chose this one because it was new and I thought for the client it would suit the best as a lot of data was involved.

So I recently started using Spring WebFlux and Project Reactor as stated in this post. One more thing I came across as I was debugging why a certain job was not running was that if you do not catch all exceptions and do not have a doOnError statement it will just keep that thought hidden from you and all to itself.

I have gotten some experience using the Flow constructs in a real scenario and learned some lessons. Therefore I wanted to make some code changes to my original design.

So I learned this the hard way, but in reactive programming, aka my WebFlux project. Do not ever use Void as a type. Just wrap it in something you can propagate like Object, String or Boolean or something else.