Backend Technologies · Java
Spring — Free Learning Resources
Free, printable resources for Spring — practice problems, quick-reference cheatsheet, and an interview prep sheet. No sign-up required.
Spring — Practice Worksheet
Structured exercises and problems to build hands-on Spring skills. Work through key concepts step by step.
Spring — Cheatsheet
One-page quick-reference for Spring — key syntax, commands, patterns, and best practices at a glance.
Spring — Interview Sheet
Top Spring interview questions with concise answers. Get ready for any technical round with this focused prep sheet.
About Spring
The Spring Framework is the foundational Java application framework providing dependency injection, aspect-oriented programming, and integration with virtually every Java technology. It is the backbone behind Spring Boot and powers the majority of enterprise Java applications globally.
SpringCheat Sheet — What's Covered
- ✓IoC container — ApplicationContext, bean lifecycle, and scope
- ✓Dependency injection — constructor vs setter vs field injection
- ✓AOP — @Aspect, pointcuts, advice types, and common use cases
- ✓Spring MVC — DispatcherServlet, @Controller, and view resolution
- ✓Transaction management — @Transactional, propagation, and isolation
Frequently Asked Questions — Spring
What is Inversion of Control (IoC) in Spring?
IoC means the framework (not the developer) controls object creation and wiring. You declare beans via annotations or XML; Spring's IoC container instantiates them and injects dependencies — removing hard-coded coupling between classes.
What is the Spring ApplicationContext?
ApplicationContext is the central Spring container. It loads bean definitions, resolves dependencies, manages lifecycle (init/destroy callbacks), and publishes events. AnnotationConfigApplicationContext and SpringApplication (Boot) are common implementations.
When should you use AOP in Spring?
Use AOP for cross-cutting concerns — logging, security, transactions, caching — that would otherwise be duplicated across many classes. @Transactional is itself implemented as AOP advice around method calls.
What are the different Spring bean scopes?
singleton (default, one instance per container), prototype (new instance per request), request (one per HTTP request), session (one per HTTP session), and application (one per ServletContext). Scope is set with @Scope('prototype') etc.
How does Spring's transaction management work?
@Transactional on a method wraps it in a transaction. Spring uses AOP to intercept the call, begin a transaction, commit on success, and roll back on unchecked exceptions. Propagation controls what happens when a transactional method calls another.
Who Is This For?
Java developers who want to understand the core container that powers Spring Boot and build maintainable, testable enterprise applications.