Spring Boot CommandLineRunner Masterclass 🚀 Initialization, Arguments & Best Practices (47)

In this video course, you’ll learn everything about **CommandLineRunner in Spring Boot**. We’ll cover what it is, why it’s useful, and how to apply it in real projects. From initialization tasks to advanced async setups, you’ll see practical examples, testing strategies, and a full demo walkthrough at the end. Perfect for developers who want to master Spring Boot startup logic the right way.

✨ What is CommandLineRunner and how it works
🚀 Why use CommandLineRunner for startup logic
⚡ Application lifecycle overview
🔧 Basic implementation methods
💻 Accessing command line arguments
🗄️ Database initialization and seeding
📑 Multiple runners and execution order
⚙️ Conditional execution with configuration
🛡️ Error handling best practices
⚡ Real-world use cases: cache warming, service health checks
🔄 Async initialization for heavy tasks
🧪 Testing CommandLineRunner effectively
📊 Performance considerations
🆚 CommandLineRunner vs ApplicationRunner
✅ Best practices & common pitfalls
👨‍💻 Final code walkthrough demo

00:00 Introduction
00:49 What is CommandLineRunner
04:09 Application LifeCycle
04:51 Basic implementations
07:25 Accessing command-line arguments
09:11 Database initialization example
09:48 Multiple runners & execution order
14:49 Error handling & best practices
18:51 Real-world use cases
23:25 Async & advanced setups
25:34 Testing & performance
28:06 When to Use CommandLineRunner
29:09 CommandLineRunner vs ApplicationRunner
33:06 Code walkthrough demo


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