In this tutorial, you will learn how to create a new topic using Kafka Command Line Interface(CLI). 1. Open a new Terminal Window To create a new Kafka topic, using CLI you will need to use a terminal window or command-line prompt. 2. Change Directory to Kafka “bin” Folder Once a terminal window is opened,…
Read More Kafka CLI – Creating Kafka TopicsWhat is JUnit 5? JUnit 5 is actually a combination of three main elements. It’s a mix of JUnit Platform, JUnit Jupiter API, and JUnit Vintage API. Let’s break it down. JUnit Platform Think of JUnit 5 as having a solid foundation called the JUnit Platform. This platform is like the engine that gets your…
Read More What is JUnit 5? (+Video Tutorial)In this tutorial, you will learn what is Spring Cloud Vault, how to install and run HashiCorp’s Vault using three different methods: from HashiCorp website, using Homebrew, or as Docker container. What is Spring Cloud Vault? How do we store secrets safe in a distributed system? Secrets are sensitive information that you don’t want to expose…
Read More Installing and Running HashiCorp’s Vault for Spring CloudEnvironment variables are useful for configuring the behavior of an application without modifying its code. They are often used to store sensitive information such as passwords, API keys, or database credentials. However, passing environment variables to a Docker container can be tricky, especially if you want to keep them secure and avoid exposing them in…
Read More Passing Environment Variables to Docker ContainerIn this tutorial, you will learn how to return a custom error message if the conditions of the Spring Method Security are not met. To learn more about method-level security annotations read: Spring Method-Level Security with @PreAuthorize, Spring Security @Secured: Method-Level Protection, @PostAuthorize Security Annotation Example. Controller class with Spring Method Security Annotation Let’s assume…
Read More Spring Method Security: Customize Error MessageIn this tutorial, I’m going to walk you through how to execute a JUnit 5 test case from a command-line terminal without the use of Maven or Gradle. If you’re just starting out with Java or JUnit, you’re in the right place. I’ll explain everything in detail, step-by-step, so you can follow along even if…
Read More Run JUnit 5 Tests from Command Line without Maven or GradleIn this tutorial, I’m going to guide you through the process of zipping and unzipping files in Java. This is a common task in many programming and data management scenarios, and it’s a skill that can be incredibly useful in a variety of contexts. Throughout this tutorial, you’ll learn how to zip a single file,…
Read More Zip and Unzip Files in JavaIn this tutorial, you will learn about Spring Bean Scopes, an important part of the Spring Framework. You will learn what they are, how they work, and when to use them. By the end, you’ll have a clear understanding of Spring Bean Scopes, helping you build better Spring applications. Introduction to Spring Beans In the…
Read More A Guide to Spring Bean ScopesIn 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 5