In this guide, I’ll show you how to create a Fat Jar with Spring Boot. Together, we’ll build a simple ‘UsersMicroservice’, then pack it into a Fat Jar. Don’t worry if you’re new, I’ll guide you step-by-step and answer your top questions along the way. Let’s get started! What is a Fat JAR? A Fat…
Read More Creating a Fat Jar App with Spring BootIn this tutorial, you will learn what the @Respository annotation is and how to use it in your Spring Boot applications. @Repository is a Spring annotation that indicates that the decorated class is a repository. A repository is a mechanism for encapsulating storage, retrieval, and search behaviour which emulates a collection of objects. How to…
Read More @Repository Annotation in Spring@Component is a Spring annotation that is used to indicate that a class is a component. Components are objects that make up the structure of an application and are responsible for performing specific tasks. They are typically used to represent services, controllers, repositories, and other types of objects that are used to implement business logic…
Read More @Component Annotation in SpringIn this tutorial, you will learn how to setup Eureka Cluster on your local computer. Although in this tutorial, I am going to setup Eureka Cluster on my local computer, you will still learn what you need to do to make Eureka run on remote server as well. What is Eureka Server Cluster? A Eureka…
Read More Eureka Server Cluster Setup TutorialIMPORTANT: This information is no longer actual. Apparently it was just a bug in Spring Initializr tool and Eureka is available with Spring Boot version 3.1.0 just fine. If you’re using Spring Initializr tool for creating Spring Boot projects, you might have noticed a change. In Spring Boot version 3.1.0, the tool no longer allows…
Read More Eureka Discovery with Spring Boot 3.1.+In this tutorial, I will share with you how to implement user look-up and authentication using Keycloak’s User Storage SPI. For starters, SPI stands for Service Provider Interface, and it is a way to write extensions to Keycloak to connect to external user databases and credential stores. In this tutorial, we will make Keycloak load…
Read More Keycloak User Storage SPI Example with Remote ServiceThe @DisplayName annotation is used to provide a custom name for your JUnit 5 test method. Let’s have a look how it is used in Java code. Below, is a very simple code example of a JUnit 5 test method. Notice how the @DisplayName annotation is used to provide a custom name for the text…
Read More @DisplayName Annotation in JUnit 5When we do integration testing of our Spring Boot application, we sometimes need to make it load an alternative configuration. For example, we might need to run and test our application on a different port number, make it connect to a database as a different user or even make it connect to a different database.…
Read More @TestPropertySource Annotation ExampleIf you are using Docker Desktop on Windows 10, you might encounter an error message that says “Docker Desktop stopped”. This can be frustrating and prevent you from running your containers and applications. In this tutorial, I will explain what causes this error and how to solve it in four easy steps. Step 1: Enable…
Read More How to Fix Docker Desktop Stopped Error on Windows 10Docker is a popular tool for creating and running containers, which are isolated environments that can run applications and services without affecting the host system. Docker makes it easy to deploy, manage, and scale your applications across different platforms and environments. In this tutorial, I will explain how to install Docker on Ubuntu 22.04, which…
Read More How to Install Docker on Ubuntu 22.04This tutorial will guide you through the process of running Unit Tests and Integration Tests separately in a Maven-based Spring Boot application. We will use the JUnit Tag feature to group our test cases and separate Unit Tests from Integration Tests. To learn more, check out the Test Java code tutorials page. Create your tests…
Read More Running Unit Tests and Integration Tests Separately in Spring BootIn this tutorial, you will learn how to use the @Tag annotation in JUnit 5 for organizing and running your unit tests. By the end of this tutorial, you’ll have a solid understanding of the @Tag annotation, its benefits, and how to apply it effectively in your own test cases. Let’s dive in! What is…
Read More @Tag Annotation: Organizing and Running Tests in JUnit 5Welcome, and thank you for choosing this tutorial! If you’re an absolute beginner looking to learn about integration testing for Spring Boot applications with a MySQL database server, then you’re in the right place. As you proceed through this tutorial, remember that everyone was once a beginner, and the only silly question is the one…
Read More Integration Testing with Spring Boot, MySQL and TestcontainersWelcome to your comprehensive guide for preparing for a Docker DevOps job interview. As you navigate the dynamic landscape of DevOps, mastering Docker – an integral tool in this field – will not only enhance your skills but also open up more opportunities for you. Given the increasing demand for Docker expertise in the market,…
Read More Docker Interview Questions and AnswersIn this tutorial, you will learn how to deploy a Spring Boot application and a MySQL server in separate Docker containers. By the end of this tutorial, you will know how to run your Spring Boot application in one Docker container and your MySQL server in another Docker container and how to make them communicate…
Read More Deploying a Spring Boot App and MySQL in Docker Containers