renatompf/poc_spring_reactive

Small project made in Java 21 and Spring to understand the differences between reactive and non-reactive applications

poc_spring_reactive

Description

POC made in Java 21 to learn the setup and the basics of the reactive programming using Spring and PostgresQL.

How to run it:

In order to run this project you will need Docker and Java 17 - or higher.

In order to run this project the simpler way would be to make the following:

make run

This way you will start a container running the database and the app. Everything will start automatically.

To stop it, you can simply do the following:

make stop

How to test it:

Create New Book:

localhost:8080/books

Body:

{
  "isbn": "9781491936160",
  "title": "Kafka: The Definitive Guide",
  "publisher": "OReilly Media"
}

Find All Books:

localhost:8080/books

Find Book By ID (ISBN):

localhost:8080/books/9781491936160

Find Book By Publisher:

localhost:8080/books/publisher?name=OReilly Media

Find Book By Title:

localhost:8080/books/title?title=JavaScript: The Good Parts

Find Book Where Title Contains:

localhost:8080/books/contains?content=java

Delete Book By ISBN:

localhost:8080/books/9781491936160

Lessons Learn:

1. When talking about Spring Reactive you refer to Mono<T> as a Singular Object and Flux<T> as a List of Objects.
2. Also, to have in mind when connecting to the database, the URL starts by r2dbc instead of jdbc. Example:

Reactive: r2dbc:postgresql://localhost:5432/database
Non-Reactive: jdbc:postgresql://localhost:5432/database

3. When starting you Spring service, the ddl-auto property will not work. This means that even with class annotated with @Table your tables will not be created automatically. For this, you'll need a migration tool, like Flyway - The tool used in this project - or Liquibase. Here you have a link to see the difference between both.