Spring MVC Interview Questions and Answers

Introduction

A Java programmer must know the answers to a few of the popular Spring questions before appearing for the interview. There are some popular interview questions for any level Java Programmer. For web applications Spring Framework is one of the popular Java EE frameworks. Two most popular concepts of Java programming are Aspect Oriented Programming and Dependency Injection. Let’s see mostly asked interview questions for freshers.

Questions for Spring MVC Interview:

1. What do you understand by Spring Framework?
2. What are the features of Spring Framework?
3. What is dependency injection?
4. What are the advantages of Spring Framework?
5. Name some popular and mostly used Spring Modules.
6. What is the role of Presentation, Abstraction, and Control components in MVC?
7. Explain Aspect Oriented Programming.
8. What is the difference between AspectJ AOP and Spring AOP?
9. What is Dispatcher Servlet in Spring MVC?
10. What is a Spring Bean?
11. Define Spring Bean Scope
12. Define Spring Bean.
13. What is the difference between Spring MVC and Spring Boot?
14. Why is the Spring Bean configuration file important?
15. What is the difference between WebApplicationContext in Spring MVC and ApplicationContext?
16. How can you configure any class as a Spring Bean?
17. Define Bean @Autowired annotation and Bean wiring.
18. Explain various types of Spring Bean Auto wiring.
19. Is thread safety provided by Spring bean?
20. Explain Spring Bean Controllers

Before appearing for an interview if you will know the answers to these questions, then it will be good. While reading these spring MVC interview questions for experienced and freshers you will surely like them and will not like to miss them et al. Few are those interesting questions.

Spring MVC Interview Questions & Answers for Freshers

Q1). What do you understand by Spring Framework?

Ans: With the two core concepts of Aspect-Oriented and Dependency Injection, Spring is one of the most popular and widely used Java EE frameworks. Through dependency injection, it can provide tight coupling between various components. The cross-cutting tasks such as authentication and logging can be provided through Spring framework and the aspect-oriented programming can be implemented through this as well. Spring framework is a featured framework that can provide several modules and lots of features for specific tasks such as Spring JDBC and Spring MVC. Working with Spring is quite easy and a fun activity due to the presence of a number of online communities and resources.

Q2). What are the features of Spring Framework?

Ans: Spring framework is based on two main concepts known as aspect-oriented programming and dependency injection. A few features of the Spring framework are:

• Spring framework is lightweight and with little overhead for the developers
• The container manager of the Spring framework can manage the Spring Bean life cycle and any project-specific configurations like JNDI lookup.
• It can support JDBC operations, transaction management, exception handling, and file uploading like little configurations either by using annotations or with the help of a Spring bean configuration file.
• This framework can be used to develop web applications and web services both of which can return JSON and XML responses
• Through inversion of control and dependency injection concepts, you can develop the independent components easily. Through spring containers these components can be wired easily.

Q3). What is dependency injection?

Ans: Dependency injection is a concept that is implemented through the design patterns. It can remove the hard-coded dependency and can make the application loosely coupled, maintainable and extendable. The dependency resolution can also be moved from compile time to run time through these design patterns. It provides the following benefits:

• Boilerplate Code Reduction
• Separation of Concerns
• Easy Unit Testing
• ConfigurableComponents

Google Guice can also be used for dependency injection and the processes can be automated through this. If we want to implement any additional concept along with dependency injection then Spring is the best choice for that.

Q4). What are the advantages of the Spring Framework?

Ans: Spring framework offers a number of advantages which include the following:

• The direct dependency among several components can be reduced through Spring IoC containers. They are responsible to create the beans, which are injected between the components and to reduce the dependency.
• As the business logic does not have any direct dependency on the implementation class of actual resource so it becomes quite easier to write the Unit test cases. The test configurations can be easily written and the configurations can be injected easily for testing purposes.
• The amount of boilerplate code is also reduced e,g. to open or close the resource or to initialize a JdbcTemplate class can also remove the boilerplate code required in JDBC programming.
• Spring framework can help us keep the application lightweight say e.g if the Spring transaction management feature is not required, then the user does not to add that dependency to the project.
• Spring framework can support a number of Java EE framework features even more than Spring is always top of the technologies like to write better naïve Android applications user can use Spring projects for Android. So it can be a complete package and the user need not have any separate package for the work.

Q5). Name some popular and mostly used Spring Modules.

Ans: Some important and mostly used Spring modules are:

• Spring Context- Used for Dependency Injection
• Spring AOP- Used to implement aspect-oriented programming
• Spring DAO- Used for database operations with the help of DAO patterns
• Spring JDBC- uSed for DataSource and JDBC support
• Spring ORM- Used for creating web applications
• Spring Web Module- Used to create the web applications
• Spring MVC- It is also known as Model-View-Controller used to create and implement the web applications

Q6). What is the role of Presentation, Abstraction, and Control components in MVC?

Ans: Abstraction: This is about what the application does and its core functions related to the business.

Presentation: This is how the application's functions are shown to users, like the interface they interact with.

Control: This keeps everything in sync between what the app does and how it looks to users. It also communicates with other parts of the system.

Q7). Explain Aspect Oriented Programming.

Ans: Some cross-cutting concerns for any enterprise-level application like transaction management, data validation, authentication, and logging in for various application modules and objects are most valuable. In the case of object-oriented programming such application modularity is implemented by classes while in AOP it is achieved by Aspects.

Q8). What is the difference between AspectJ AOP and Spring AOP?

Ans: The industry standard implementation of Aspect-oriented programming is called AspectJ while implementation of AOP can also be done with the help of Springs. The major differences between AspectJ and Spring AOP are listed below:

• The use of AspectJ is easier than Spring AOP as the weaving process is not required in this implementation.
• Spring AOP itself supports AspectJ as the weaving process is not involved so familiarity with AspectJ can be helpful in Spring AOP itself.
• Only Proxy-based AOPs are supported in Spring AOP so it is used only for join points of method execution. AspectJ supports pointcuts of all types.
• Unlike Aspect, the Spring AOP can only be applied to the Spring Context beans.

Q9: What is the Dispatcher Servlet in Spring MVC? 

Ans: The Dispatcher Servlet acts as the central coordinator in the Spring MVC framework. It receives incoming web requests, routes them to the appropriate components such as models, controllers, and views, and ensures that the correct responses are sent back to the clients. Essentially, it manages the entire operation and flow of the application.

Q10). What is a Spring Bean?

Ans: Any class of Spring framework, which is initialized by Spring IoC container is known as Spring Bean. We can get the Spring Bean instance through Spring Application Context. The life cycle of Spring Bean can be managed by Spring IoC container.

Q11). Define Spring Bean Scope

Ans: The following five are the main scopes of Spring Beans:

• Prototype: Whenever a bean is requested a separate prototype is created each time
• Request: It is quite like prototype scope while used for web applications only. For each HTTP request a new bean instance is created.
• Singleton: For every container only one instance of the bean is created and they act as the default scope for the bean containers. In these instances, the beans cannot have shared instance variables. As these instances are not threaded safe so can lead to data inconsistency.
• Session: For every HTTP session a bean is created by the containers
• Global-session: For Portlet applications the global session is created

The Spring framework is extendable user can also create his own scope as well. While the Spring defined scope is also used by the developers. The “scope” attribute of the bean element is used to define its scope. The above-listed ones are mostly asked for spring MVC interview questions and answers. Apart from these there can be other spring MVC interview questions as well. You can find other questions to clear the interview.

Spring MVC Interview Questions & Answers  for Experienced

Q12: What is the difference between Spring MVC and Spring Boot?

A: 

Features	Spring Boot	Spring MVC
Working	Simplifies creating standalone, dynamic web applications and supports fast development.	Part of the core Spring framework, it helps build web applications using the Model-View-Controller (MVC) design.
Build	A framework that makes it easy to start using the Spring framework with little setup.	A web framework built on top of the Java Servlet API.
Productivity	Saves time and increases productivity for developing standalone applications and Spring-based projects.	Used to create web applications that run on servlet containers like Tomcat.

Q13). Define Spring Bean.

Ans: When a normal Java class starts with an IoC container it is called Spring Bean. To get the Spring Bean instance we can use Spring Application Context. The life cycle of Spring Bean is managed by the IoC container, it also manages the scope of bean and the dependencies required in case of bean injection in any module.

Q14). Why is the Spring Bean configuration file important?

Ans: All beans that are initialized by Spring Context are defined in the Spring Bean configuration file. When an instance of Spring Application Context is created it reads the Spring bean XML file and initializes all of them. The context is initialized once in the bean life cycle and then it can be used to get different bean instances throughout its lifecycle. This file not only contains Spring Bean configuration instead it also contains Spring MVC view resolvers, interceptors, and other annotations that can support other configuration-based elements.

Q15: What is the difference between WebApplicationContext in Spring MVC and ApplicationContext?

A: 

Features	Application Context	Web Application Context
Configuration	Configured using application Context.xml or through annotations like @ Configuration and @ Bean.	Configuration typically involves XML files named *-servlet.xml, tailored for web-specific setups.
Working	Meant for standalone applications, handling configuration and components.	Specifically designed for web applications running within containers like Tomcat or Jetty, managing web-related configurations and components.
Example	Desktop Applications	RESTful APIs

Q16). How can you configure any class as a Spring Bean?

Ans: We can configure any Java class to Spring Bean by the following three ways:

1. XML Configuration: XML configuration is the most popular one and the bean element can be used in the contextfile to configure a Spring Bean. The example is given below:
2. Java-Based Configuration: The beans can also be configured by using @Bean annotations. It is used with @Configuration classes through which you can configure the bean. An example is given below:
3. Annotation-Based Configuration: We can use @Service, @Component, @Controller, and @Repository annotations with the normal Java classes if we want to configure them as a Bean. To provide such annotation the base package class location has to be specified for these classes. An example is given below:

Q17). Define Bean @Autowired annotation and Bean wiring.

Ans: The complete process of injecting a bean dependency at the time of its initialization is known as Spring Bean wiring. Though the user can do the explicit wiring for all the beans in the spring framework you can also use auto wiring. For this, the annotation @Autowired can be used with filesautowiring by type. For this, we will also have to enable annotation-based configuration located in the Spring bean file

Q18). Explain various types of Spring Bean Auto wiring.

Ans: In the Spring framework, the following four types of auto wiring is defined:

• Autowire byname
• Autowire byType
• Autowire by constructor
• Autowire by @Autowired and @Qualifier annotations

Q19). Is thread safety provided by Spring bean?

Ans: The default scope of any bean in the Spring framework is a singleton, so only one instance per context can be there. Therefore the class-level variables that can be updated through the thread may lead to inconsistent data so Spring beans are not threaded safe. To achieve thread safety the bean scope can be changed to prototype, request, or session and for that, the performance may have to be compromised.

Q20). Explain Spring Bean Controllers.

Ans: Like MVC design patterns Spring Bean Controller class takes care of the requests coming from any client and it sends them to the configured resources which can handle it. The front controller class org. spring framework.web.servlet.DispatcherServlet initializes the contexts on the basis of spring bean configurations. A Controller class can handle various kinds of client requests on the basis of request mapping. By using @Controller annotation the controller class can be created.

Conclusion

This blog covers the questions which you can read and solve if you want to crack the interview for Spring bean professional. Java professionals also have to get practical knowledge along with theoretical concepts. The questions are covered for both fresher and experienced professionals and you can also find many others questions if you want to be a proficient Java developer and want to crack Spring interview.