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In this Swift tutorial, I’ll show you how to add new functionality to existing Swift classes using class extensions. It’s a powerful feature in Swift that lets you add your own methods or computed properties to already-defined classes, making them more versatile. Let’s start with a very simple example. Creating a Simple Extension In Swift,…

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In this tutorial, you will learn how to generate a custom JSON Web Token(JWT) and how to add and validate custom JWT Claims using the io.jsonwebtoken library. The JWT token generated in this tutorial will be signed with a SecretKey, making it secure and tamper-proof. Also, this tutorial assumes you have prior knowledge of creating…

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In this lesson, you will learn how to consume messages or how to read messages from Apache Kafka topic using Kafka Consumer Command Line Interface(CLI). To learn how to produce or send messages to Kafka topic, please read the following tutorial: Kafka Producer CLI – Produce/Send message to Kafka topic. Consuming Messages From the Beginning…

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In this tutorial, you will learn how to delete Apache Kafka topics using the Kafka Command-line Interface(CLI). Before Deleting Kafka Topic Before deleting a Kafka topic, there are a few things you should keep in mind: Deleting a topic is permanent: Once you delete it, it is gone forever. There is no way to undo…

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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 Cloud

Environment 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…

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In 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 Message

In 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,…

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