To prepare for a Java Spring Boot interview, it’s essential to cover a wide range of topics related to Spring Boot and general Java backend development. Here’s a structured list of key topics to help you prepare effectively:
1. Core Spring Framework Concepts
- Inversion of Control (IoC) and Dependency Injection (DI)
- Spring Bean lifecycle (Singleton, Prototype, etc.)
- Application Context vs BeanFactory
- Aspect-Oriented Programming (AOP) in Spring
2. Spring Boot Basics
- Spring Boot vs Spring Framework: differences, benefits, and use cases.
- Spring Boot Auto-configuration: How it works and customizing it.
- Starter Dependencies: Purpose and common ones (e.g., spring-boot-starter-web, spring-boot-starter-data-jpa).
- Spring Boot CLI and
spring-boot-starterprojects. - Application Properties and YAML configurations: Externalized configurations, profiles.
3. RESTful Web Services
- Creating REST APIs with Spring Boot (
@RestController,@RequestMapping,@PathVariable,@RequestBody) - Handling HTTP methods: GET, POST, PUT, DELETE.
- Exception Handling in Spring Boot REST API (
@ControllerAdvice,@ExceptionHandler) - HATEOAS: Using Hypermedia as the Engine of Application State in REST APIs.
- Versioning REST APIs.
- Validation using
@Valid,@NotNull,@NotEmpty, and custom validation annotations.
4. Spring Data JPA and Hibernate
- Entity mapping with Hibernate (JPA Annotations:
@Entity,@Id,@OneToMany,@ManyToOne, etc.) - Repositories in Spring Data JPA:
CrudRepository,JpaRepository, and custom queries. - JPQL vs Native Queries.
- Pagination and Sorting in Spring Data JPA.
- Transaction Management with
@Transactional. - Lazy vs Eager loading in Hibernate.
5. Database Integration
- H2 Database (in-memory database) for testing.
- MySQL, PostgreSQL integration with Spring Boot.
- Flyway and Liquibase for database versioning.
- Connection pooling (HikariCP).
6. Spring Security
- Securing Spring Boot applications: Role-based security, JWT-based security.
- OAuth2 integration with Spring Security.
- Custom Authentication and Authorization mechanisms.
- CSRF protection, CORS configuration.
7. Spring Boot Testing
- Unit testing with JUnit and Mockito.
- Integration Testing using Spring Boot’s
@SpringBootTest. - Mocking dependencies in tests with
@MockBean,@WebMvcTest. - Testing REST controllers with
MockMvc.
8. Microservices with Spring Boot
- Building Microservices: Design principles, splitting monoliths.
- Service discovery and registry: Using Eureka, Consul.
- Circuit Breakers and Resilience: Using Resilience4j, Hystrix.
- Inter-service communication: REST vs Feign clients.
- Distributed tracing and logging (Zipkin, Sleuth).
- Spring Cloud Config for centralized configuration management.
9. Messaging
- Spring Boot with Apache Kafka, RabbitMQ, ActiveMQ.
- Asynchronous processing: Using
@Async,@EnableAsync. - Messaging patterns: Event-driven architecture.
10. Spring Boot Actuator and Monitoring
- Spring Boot Actuator: Exposing metrics, health checks, auditing.
- Customizing Actuator endpoints.
- Prometheus and Grafana for monitoring.
- Integration with Micrometer.
11. Deployment and CI/CD
- Packaging Spring Boot apps: JAR vs WAR.
- Dockerizing Spring Boot applications.
- AWS or other cloud service integrations.
- CI/CD pipelines with Jenkins or GitLab CI.
- Heroku or AWS Elastic Beanstalk for easy deployment.
12. Performance and Optimization
- Caching using Spring Cache, EhCache, or Redis.
- Database connection pooling (e.g., HikariCP).
- Lazy Loading vs Eager Loading in JPA.
- Profiling Spring Boot applications for performance bottlenecks.
13. Concurrency
- Concurrency in Java: Threading, ExecutorService, Future.
- Concurrency support in Spring: Task Executors,
@Async,@Scheduled.
14. Reactive Programming (optional)
- Introduction to Spring WebFlux.
- Using Mono and Flux for building non-blocking applications.
Preparing on these topics will ensure you’re well-rounded in core Spring Boot areas and advanced topics, making you ready for most Java Spring Boot interviews. You can further tailor your preparation based on the company or specific project requirements you’re interviewing for.