Dependency Injection Questions
Constructor Injection (Preferred)
- Immutability, testability
- Explicit dependencies
- Required dependencies enforced
Bean Lifecycle
- Instantiation
- Populate properties (DI)
- BeanPostProcessor (before)
- @PostConstruct
- Bean ready
- @PreDestroy
Bean Scopes
- singleton: one per container (default)
- prototype: new per request
- request: one per HTTP request
Key Points
- Understanding Spring Boot Questions is essential for production systems
- Always consider scalability and maintainability
- Test thoroughly before deploying to production
- Monitor performance and set up alerting
Common Patterns
- Validation: Always validate input at the boundary
- Error Handling: Use structured error responses
- Logging: Log key events for debugging
- Testing: Unit, integration, and load tests
- Documentation: Keep docs updated with code changes
Spring Annotations
Stereotype
@Controller, @RestController, @Service, @Repository, @Component
Configuration
@Configuration, @Bean, @Value, @Profile
@Transactional
- Rollback on RuntimeException (unchecked) by default
- Propagation: REQUIRED, REQUIRES_NEW, NESTED
- @Transactional is AOP-based proxy
Key Points
- Understanding Spring Boot Questions is essential for production systems
- Always consider scalability and maintainability
- Test thoroughly before deploying to production
- Monitor performance and set up alerting
Common Patterns
- Validation: Always validate input at the boundary
- Error Handling: Use structured error responses
- Logging: Log key events for debugging
- Testing: Unit, integration, and load tests
- Documentation: Keep docs updated with code changes
Practice Problems
Design and implement a solution for Spring Boot Questions in a backend system. Consider scalability, error handling, and production readiness.
Solution
// Spring Boot Questions implementation
// Key aspects: validation, error handling, logging, testing
public class SpringBootQuestions {
// Production-ready implementation
}Identify and handle edge cases for Spring Boot Questions. What happens under high load, with invalid input, or during failures?
Solution
// Edge case handling:
// 1. Null/empty input -> validation
// 2. High load -> rate limiting, queuing
// 3. Failures -> retries, circuit breaker
// 4. Concurrent access -> locks, idempotencyWrite a testing strategy for Spring Boot Questions. Include unit tests, integration tests, and performance tests.
Solution
// Test plan:
// - Unit: 80% coverage target
// - Integration: API contracts
// - Performance: latency, throughput
// - Chaos: failure injectionQuiz
1. Preferred DI method in Spring?
2. @Transactional rolls back on?
3. What is the primary purpose of Spring Boot Questions?
4. What is a common mistake when implementing Spring Boot Questions?
Flashcards
Question
Preferred DI method?
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Answer
Constructor injection - explicit, immutable, testable
Question
@Transactional rollback?
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Answer
Rolls back on RuntimeException by default
Question
What is Spring Boot Questions?
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Answer
Spring Boot Questions is a key concept in backend development.
Question
When to use Spring Boot Questions?
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Answer
Use Spring Boot Questions when building production systems that require reliability, scalability, and maintainability.
Question
Spring Boot Questions best practices
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Answer
Follow SOLID principles, write clean code, test thoroughly, document decisions, and monitor in production.
Revision Notes
Key Takeaways
- 1.Constructor injection preferred
- 2.Bean lifecycle: instantiation -> DI -> init -> ready
- 3.@Transactional rolls back on RuntimeException
- 4.Stereotype: @Controller, @Service, @Repository
Interview Tips
- •Explain why constructor injection is better
- •Know bean lifecycle stages
- •Discuss @Transactional pitfalls
Cheat Sheet
Spring Boot Interview
- DI: Constructor injection (preferred)
- Scopes: singleton (default), prototype, request, session
- @Transactional: Rolls back on RuntimeException