Spring IoC Container | Spring Boot Interview Questions 🔥

Are you preparing for Spring Boot interview questions or brushing up on Spring Core fundamentals? 🚀 This masterclass explains the Spring IoC Container and the complete bean lifecycle step by step using a simple Car Analogy. You’ll learn how beans are created, dependencies injected, lifecycle callbacks executed, and how post-processors like BeanFactoryPostProcessor and BeanPostProcessor work in real-time. 🔑 What You Will Learn What is the Spring IoC Container? ApplicationContext vs BeanFactory How Dependency Injection (DI) works under the hood Spring Bean Lifecycle explained with @PostConstruct and @PreDestroy Bean Scopes: Singleton vs Prototype Role of BeanFactoryPostProcessor (modifies bean definitions before creation) Role of BeanPostProcessor (modifies beans after creation) Real-world examples: @Autowired Key Spring Boot Interview Questions around IoC, DI, and lifecycle 🚗 Car Analogy – Making Spring Easy Car = Main bean Battery, Engine, Tyre = Dependencies IoC Container = Factory that builds & assembles the Car Dependency Injection = Factory injects battery, engine, tyre before handing over the Car @PostConstruct = Unlock + start engine @PreDestroy = Lock + shut down BeanPostProcessor (Mechanic) = Adds upgrades after the car is built BeanFactoryPostProcessor (Factory Manager) = Tweaks the recipe before building 🕒 Chapters 00:00 - Spring IoC Container & Lifecycle 00:52 - Standalone Spring Boot Project (Car Analogy) 02:10 - Life Without IoC 04:51 - What is a Spring Container? 06:26 - Defining Beans with @Component 07:05 - Dependency Injection (DI) 08:20 - ApplicationContext 11:15 - Container Lifecycle Start 11:43 - @SpringBootApplication & run() 13:10 - @ComponentScan & @Configuration 14:15 - Annotation-Based Config 15:04 - How a Spring Application Works 15:53 - Spring Bean Lifecycle 17:42 - @PostConstruct Example 20:42 - Closing the Container 21:11 - @PreDestroy Example 24:53 - What is BeanDefinition? 29:17 - Singleton vs Prototype Scope 31:23 - BeanFactoryPostProcessor 34:28 - static @Bean Explained 36:00 - Changing Bean Definitions 39:24 - BeanPostProcessor vs BeanFactoryPostProcessor 40:23 - @PreDestroy & Prototype Conflict 41:32 - Work of BeanPostProcessor 45:08 - postProcessBeforeInitialization 47:22 - Changing a Bean After Creation 52:05 - postProcessAfterInitialization 52:55 - Container Lifecycle End 53:10 - Real-World Uses of BeanPostProcessor 📚 Why Watch This Video? Covers Spring Core [FOUNDATION] concepts Explains IoC Container + Bean Lifecycle in detail Uses real-world Car Analogy to simplify learning Interview Prep: Most asked Spring Boot interview questions included Hands-on Spring Boot coding demo For More free/paid courses visit www.seleniumexpress.com #springboot #springcore #springframework #springboottutorial 🎓 Related Courses – For reference 📘 Java Streams & Lambda Expressions    • Stream API in Java : Foundation |  Java 8   ⚡ Reactive Java with Project Reactor    • Reactive Programming 01 - Java Stream Vs R...   🔁 Generics in Java Explained    • From Beginner to Expert:  Why Java Generic...   🌐 Spring Boot Crash Course    • Spring Vs Spring Boot - Why Spring Boot ? ...   ▶️ Spring Boot Microservices    • What the heck is Spring Cloud ? An Introdu...   ▶️ Apache Kafka Essentials    • Apache Kafka Tutorial for Beginners - Setu...   ▶️ Spring Bootcamp (FREE)    • Spring Framework 6 - project setup | Sprin...   ▶️ Spring Live Mock Interview    • Java interview questions and answers for e...   Feel free to ask for support. Email me at seleniumexpress@gmail.com For More free/paid courses visit www.seleniumexpress.com Facebook   / seleniumexpress   Facebook support Group “SeleniumExpress - Support"   / 187000222361579   Follow me on Insta   / selenium_express   🔔 Subscribe for More