Top questions with answers asked in MNC on Advance Java Spring

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Advanced Java Sprint interview questions along with their answers:

  1. What is the Spring Framework, and what are its core features?
    • Answer: The Spring Framework is an open-source Java framework that provides comprehensive infrastructure support for developing enterprise Java applications. Its core features include:
      • Dependency Injection (DI): Spring’s IoC container manages object dependencies and provides them to objects at runtime, reducing coupling and improving testability.
      • Aspect-Oriented Programming (AOP): Spring AOP allows developers to apply cross-cutting concerns, such as logging, security, and transaction management, to multiple components in a modular and reusable manner.
      • Spring MVC: Spring MVC is a web framework built on top of the Spring Framework for building web applications using the Model-View-Controller (MVC) architectural pattern.
      • Transaction Management: Spring provides support for declarative transaction management, allowing developers to define transaction boundaries and propagation behavior using annotations or XML configuration.
      • Data Access: Spring provides integration with JDBC, JPA, Hibernate, and other ORM frameworks for simplified database interactions and data access.
  2. What is Dependency Injection (DI) in Spring, and how is it implemented?
    • Answer: Dependency Injection (DI) is a design pattern and a core concept in the Spring Framework that facilitates loose coupling and promotes the principle of inversion of control (IoC). In DI, dependencies of a class are provided externally (injected) rather than created internally. Spring implements DI through its IoC container, which manages the creation and wiring of objects (beans) and their dependencies. DI can be implemented in Spring using constructor injection, setter injection, or field injection, where dependencies are provided to beans either through constructor arguments, setter methods, or directly injected into fields using annotations.
  3. What is Spring Boot, and how does it simplify application development?
    • Answer: Spring Boot is a framework within the Spring ecosystem that simplifies the development of stand-alone, production-grade Spring-based applications. It provides auto-configuration, opinionated defaults, and out-of-the-box integration with other Spring projects and third-party libraries, allowing developers to focus on writing business logic rather than boilerplate configuration. Spring Boot reduces development time and effort by providing features such as embedded servers, dependency management, production-ready metrics, health checks, and easy deployment options.
  4. What is Spring Security, and how does it provide authentication and authorization?
    • Answer: Spring Security is a powerful and customizable security framework for securing Java-based applications. It provides comprehensive authentication and authorization mechanisms to protect web applications, REST APIs, and method invocations. Spring Security supports various authentication mechanisms, including form-based authentication, HTTP Basic/Digest authentication, OAuth, and OpenID Connect. It also allows developers to define access control rules and authorization policies using annotations or configuration, ensuring that only authenticated and authorized users can access protected resources.
  5. What are Spring Beans, and how are they defined in a Spring application context?
    • Answer: Spring Beans are the objects managed by the Spring IoC container. They are defined in a Spring application context, which is an XML file (applicationContext.xml) or Java-based configuration class that contains bean definitions and their dependencies. Spring Beans can be defined using XML-based configuration (<bean> elements), annotation-based configuration (@Component, @Service, @Repository, @Controller), or Java-based configuration (@Configuration, @Bean). The Spring IoC container is responsible for instantiating, configuring, and managing the lifecycle of Spring Beans based on their defined scope (e.g., singleton, prototype, request, session).