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LetsGit.IT/Categories/Spring
Springmedium

BeanFactory vs ApplicationContext: what’s the practical difference?

Tags
#spring#ioc#applicationcontext#beanfactory
Back to categoryPractice quiz

Answer

BeanFactory is the minimal IoC container (lazy by default). ApplicationContext builds on it with extra features like internationalization, event publishing, and eager singleton initialization. In most apps you use ApplicationContext.

Advanced answer

Deep dive

Expanding on the short answer — what usually matters in practice:

  • Context (tags): spring, ioc, applicationcontext, beanfactory
  • Lifecycle: what happens at runtime (render/build, request/response, background jobs).
  • Caching: where cache lives, cache keys, how to invalidate without chaos.
  • Security: authn/authz, secrets, attack surface (SSRF/CSRF).
  • Explain the "why", not just the "what" (intuition + consequences).
  • Trade-offs: what you gain/lose (time, memory, complexity, risk).
  • Edge cases: empty inputs, large inputs, invalid inputs, concurrency.

Examples

A tiny example (an explanation template):

// Example: discuss trade-offs for "beanfactory-vs-applicationcontext:-what’s-the-pr"
function explain() {
  // Start from the core idea:
  // BeanFactory is the minimal IoC container (lazy by default). ApplicationContext builds on i
}

Common pitfalls

  • Too generic: no concrete trade-offs or examples.
  • Mixing average-case and worst-case (e.g., complexity).
  • Ignoring constraints: memory, concurrency, network/disk costs.

Interview follow-ups

  • When would you choose an alternative and why?
  • What production issues show up and how do you diagnose them?
  • How would you test edge cases?

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