Spring Interview Questions

1.      What is Spring Framework?

Spring Framework is an open-source application development framework for Java. It provides a comprehensive set of features to help developers build robust, maintainable, and testable applications.

2.      What are the key features of Spring Framework?

The key features of Spring Framework include dependency injection, aspect-oriented programming, data access and transaction management, and support for web and enterprise applications.

3.      What is the difference between Spring Framework and other Java frameworks?

Spring Framework is a lightweight, non-invasive framework that aims to simplify Java development by providing a consistent programming model. Other Java frameworks, such as JavaEE, provide a more complex and feature-rich set of tools, but are also more complex to use and configure.

4.      What is dependency injection in Spring Framework?

Dependency injection is a design pattern that allows objects to be constructed and their dependencies to be provided by an external source, rather than being constructed and managed by the object itself. Spring Framework provides a powerful dependency injection mechanism that allows developers to easily manage the dependencies of their objects.

5.      What is aspect-oriented programming in Spring Framework?

Aspect-oriented programming (AOP) is a programming paradigm that allows developers to modularize cross-cutting concerns, such as logging, security, and transaction management, into separate, reusable components. Spring Framework provides a comprehensive AOP implementation that allows developers to easily apply these concerns to their applications.

6.      How does Spring Framework support data access and transaction management?

Spring Framework provides a set of data access and transaction management features that allow developers to easily interact with databases and manage transactions. These features include support for JDBC, JPA, and Hibernate, as well as a powerful transaction management framework.

7.      How does Spring Framework support web and enterprise applications?

Spring Framework provides a set of web and enterprise features that allow developers to easily build web and enterprise applications. These features include support for web services, REST, and MVC, as well as support for enterprise integration patterns and messaging.

8.      What is Spring Boot?

Spring Boot is a framework that allows developers to easily build production-ready Spring applications. It provides a set of conventions and sensible defaults that allow developers to quickly get started with building their applications.

9.      What is Spring MVC?

Spring MVC is a module of the Spring Framework that provides a Model-View-Controller (MVC) architecture for building web applications. It allows developers to easily handle HTTP requests and generate HTTP responses.

10.   What is Spring Data?

Spring Data is a set of libraries that allow developers to easily interact with databases and other data sources. It provides a consistent programming model for different data access technologies, such as JDBC, JPA, and MongoDB.

11.   What is Spring Security?

Spring Security is a framework that provides authentication and authorization features for web applications. It allows developers to easily secure their applications and protect them from security threats.

12.   What is Spring AOP?

Spring AOP is a module of the Spring Framework that provides aspect-oriented programming (AOP) support. It allows developers to easily apply cross-cutting concerns, such as logging, security, and transaction management, to their applications.

13.   What is the BeanFactory in Spring Framework?

The BeanFactory is a lightweight container that provides the basic support for dependency injection and lifecycle management for objects in a Spring application.

14.   What is the ApplicationContext in Spring Framework?

The ApplicationContext is an extension of the BeanFactory that provides additional

15.   What is the difference between BeanFactory and ApplicationContext in Spring Framework?

The BeanFactory is a lightweight container that provides basic support for dependency injection and lifecycle management, while the ApplicationContext is a more advanced container that provides additional features such as internationalization, event handling, and support for annotation-based configuration.

16.   What is Spring Bean?

A Spring Bean is an object that is managed by the Spring container. It is created, configured, and managed by the container, and can be used to access other beans and services.

17.   How do you configure a Spring Bean?

A Spring Bean can be configured by using XML configuration, Java-based configuration, or annotation-based configuration. XML configuration involves defining beans in an XML file, Java-based configuration involves defining beans using Java code, and annotation-based configuration involves using annotations to define beans and their properties.

18.   What is the difference between @Component, @Repository, @Service and @Controller in Spring?

@Component is a general-purpose annotation that can be used for any class that is managed by the Spring container. @Repository is a specialization of @Component for data access objects. @Service is a specialization of @Component for service classes. @Controller is a specialization of @Component for controllers in a Spring MVC application.

19.   How does Spring handle transactions?

Spring handles transactions using the Spring Transaction abstraction, which allows developers to declaratively manage transactions using either programmatic or declarative approaches. Spring supports various transaction management options like programmatic, declarative, annotation-based and AspectJ based.

20.   What is the difference between @Autowired and @Inject in Spring?

@Autowired and @Inject are both used for dependency injection in Spring. @Autowired is a Spring-specific annotation, while @Inject is a standard annotation defined by JSR-330. Both annotations can be used to inject dependencies into a class, but @Autowired has additional features such as support for autowiring by type and by name.

21.   How do you handle exceptions in Spring MVC?

Exceptions in Spring MVC can be handled by using the @ExceptionHandler annotation to define a method that handles specific exceptions, or by using a global @ControllerAdvice class to handle exceptions across multiple controllers.

22.   What is Spring Data JPA?

Spring Data JPA is a module of the Spring Framework that provides a consistent programming model for interacting with databases and other data sources. It is built on top of the Java Persistence API (JPA) and provides additional features such as automatic generation of repository implementations and support for query methods.

23.   What is Spring WebFlux?

Spring WebFlux is a non-blocking, reactive programming model for building web applications in Spring Framework. It allows developers to build highly scalable, responsive, and resilient web applications using asynchronous and non-blocking techniques.

24.   What is Spring Security OAuth?

Spring Security OAuth is a module of the Spring Security framework that provides support for OAuth 2.0, an open standard for secure token-based authentication and authorization. It allows developers to easily secure their applications using OAuth 2.0 providers such as Facebook, Google, and Twitter.

25.   What is Spring Cloud?

Spring Cloud is a set of libraries and tools that help developers build cloud-native applications using Spring Framework. It provides features such as service discovery, load balancing, and configuration management, as well as support for popular cloud platforms such as AWS, Azure, and Google Cloud.

26.   What is Spring Batch?

Spring Batch is a module of the Spring Framework that provides a comprehensive framework for developing batch applications. It allows developers to define and execute batch jobs, as well as manage the input, output, and processing of data.

27.   What is Spring AMQP?

Spring AMQP is a module of the Spring Framework that provides support for Advanced Message Queuing Protocol (AMQP), a standard for messaging middleware. It allows developers to easily send and receive messages using AMQP-compliant message brokers such as RabbitMQ and Apache Kafka.

28.   How does Spring handle security?

Spring provides a comprehensive security framework that allows developers to easily secure their applications. It supports authentication, authorization, and access control, as well as support for common security standards such as OAuth 2.0 and SAML.

29.   What is a Spring BeanPostProcessor?

A Spring BeanPostProcessor is an interface that allows developers to perform operations on beans before and after they are initialized by the Spring container. It can be used to perform tasks such as logging, auditing, and proxying.

30.   What is a Spring BeanFactoryPostProcessor?

A Spring BeanFactoryPostProcessor is an interface that allows developers to perform operations on the BeanFactory before it starts to create and configure beans. It can be used to perform tasks such as registering custom beans, modifying bean definitions, and registering custom property editors.

31.   What is a Spring ApplicationListener?

A Spring ApplicationListener is an interface that allows developers to register for and receive application events, such as context refresh and startup events, in their beans. This can be used for tasks such as initializing resources, performing custom logic, and registering for external services.

32.   What is Spring Boot Actuator?

Spring Boot Actuator is a sub-project of Spring Boot that provides a set of features for monitoring and managing Spring Boot applications. It provides endpoints for monitoring application health, metrics

33.   What is Spring Boot Starter?

Spring Boot Starter is a set of convenient starter POMs that provide a quick way to add common dependencies to a Spring Boot project. These dependencies are grouped by functionality, such as web, data, and security, and can be easily included in a project by adding the corresponding Spring Boot Starter to the project's dependencies.

34.   What is the difference between @Bean and @Component in Spring?

@Bean and @Component are both used to define beans in a Spring application. @Bean is a method-level annotation that is used to define a bean within a @Configuration class, while @Component is a class-level annotation that is used to define a bean that is detected and managed by the Spring component scanning process.

35.   How does Spring handle configuration?

Spring provides a flexible and powerful configuration mechanism that allows developers to easily manage the configuration of their applications. It supports various configuration styles such as XML, Java-based, and annotation-based configuration. Spring also provides a centralized configuration management feature called Spring Cloud Config.

36.   What is Spring Data REST?

Spring Data REST is a module of the Spring Data project that allows developers to easily expose their data repositories as RESTful web services. It provides a set of conventions and sensible defaults that allow developers to quickly get started with building RESTful web services for their data repositories.

37.   What is Spring WebSocket?

Spring WebSocket is a module of the Spring Framework that provides support for WebSocket, a protocol for real-time, bidirectional communication between a browser and a server. It allows developers to easily build web applications that support real-time, low-latency communication.

38.   What is Spring Security SAML?

Spring Security SAML is a module of the Spring Security framework that provides support for Security Assertion Markup Language (SAML), a standard for exchanging authentication and authorization information between different systems. It allows developers to easily secure their applications using SAML-compliant identity providers such as ADFS and Okta.

39.   What is Spring Cloud Netflix?

Spring Cloud Netflix is a set of libraries and tools that provide integration with various Netflix OSS (Open-source Software) components such as Eureka

40.   What is Spring Cloud Netflix?

Spring Cloud Netflix is a set of libraries and tools that provide integration with various Netflix OSS (Open-source Software) components such as Eureka, Ribbon, Hystrix, and Zuul. It allows developers to easily build and deploy microservices-based applications on top of a Netflix OSS stack.

41.   What is Spring Cloud Config?

Spring Cloud Config is a module of the Spring Cloud project that provides a centralized configuration management service for distributed applications. It allows developers to easily manage the configuration of their applications across multiple environments and easily refresh the configuration without having to restart the application.

42.   What is Spring Cloud Eureka?

Spring Cloud Eureka is a module of the Spring Cloud project that provides a service registry for microservices-based applications. It allows services to register themselves and discover other services, and provides load balancing and failover capabilities.

43.   What is Spring Cloud Sleuth?

Spring Cloud Sleuth is a module of the Spring Cloud project that provides distributed tracing capabilities for Spring applications. It allows developers to trace the flow of requests across multiple services, and provides support for popular tracing systems such as Zipkin and Spring Cloud Sleuth.

44.   What is Spring Cloud Gateway?

Spring Cloud Gateway is a module of the Spring Cloud project that provides a routing and API gateway for microservices-based applications. It allows developers to easily define routes, handle requests and responses, and provide security and rate-limiting capabilities.

45.   What is Spring Cloud Stream?

Spring Cloud Stream is a module of the Spring Cloud project that provides a messaging-based programming model for building event-driven microservices-based applications. It allows developers to easily connect to messaging systems such as RabbitMQ, Kafka, and Kinesis, and provides support for various messaging patterns such as publish-subscribe, request-reply, and event-driven architectures.

46.   What is Spring Cloud Contract?

Spring Cloud Contract is a module of the Spring Cloud project that provides a framework for creating and testing contracts for microservices-based applications. It allows developers to define and test contracts for APIs, and provides support for generating tests and stubs for the API based on the contracts.

47.   What is Spring Cloud Vault?

Spring Cloud Vault is a module of the Spring Cloud project that provides integration with HashiCorp Vault, a tool for managing secrets such as passwords, tokens, and certificates. It allows developers to easily manage and access secrets in a secure and centralized way, and provides integration with Spring applications.