Did you know? Spring Boot is used by 82.7% of developers for running applications and is one of the most popular Java frameworks. That’s why many Java interviews include lots of questions about Spring Boot. In fact, the top IT companies in India look for candidates with this skill. To help you succeed, we’ve put together a list of the top 50+ most commonly asked Spring Boot interview questions with answers.
These questions cover a range of topics to make sure you’re well-prepared and confident for your interview.
Get ready to impress your future employers!
Spring Boot Interview Questions for Freshers
Here are some commonly-asked Spring Boot interview questions and answers for freshers.
- What is Spring Boot?
Spring Boot is an open-source Java-based framework that is easily used to create standalone, production-grade Spring applications. It simplifies the setup and development process by providing defaults and opinions out of the box.
- What are the main features of Spring Boot?
Key features of Spring Boot include:
- Auto-configuration: Automatically configures Spring application based on the dependencies you add.
- Standalone: Create standalone Spring applications without needing a separate web server.
- Opinionated Defaults: Provides default configurations to reduce development time.
- Embedded Server: Includes embedded servers like Tomcat and Jetty.
- Production Ready: Provides metrics, health checks, and externalized configuration.
- How does Spring Boot simplify development?
Spring Boot simplifies development by,
- Providing pre-configured templates
- Reducing boilerplate code
- Auto-configuring the application based on the dependencies
- Including an embedded server
All these things make it easier to run applications.
- What is Spring Boot Starter?
A Spring Boot Starter is a set of convenient dependency descriptors you can include in your application. For example, spring-boot-starter-web includes all the dependencies needed to create a web application.
- What is Spring Boot’s role in Microservices?
This is one of the most common Spring Boot Microservices interview questions.
Spring Boot makes it easier to develop and deploy microservices by providing embedded servers and simplifying configuration with properties. Additionally, it integrates well with Spring Cloud for service discovery, load balancing, and distributed configuration.
Also Read - Top 25 Spring Boot Microservices Interview Questions with Answers
- What is the use of @SpringBootApplication annotation?
You may also come across Spring Boot Annotations interview questions like this one.
The @SpringBootApplication annotation is a convenience annotation that combines @Configuration, @EnableAutoConfiguration, and @ComponentScan. It marks the main class of a Spring Boot application.
- How do you integrate Kafka with Spring Boot?
This is one of the most important Kafka Spring Boot interview questions.
To integrate Kafka with Spring Boot, you can use the spring-kafka dependency. Then, configure Kafka properties in application.properties and use @KafkaListener to listen to Kafka topics.
- What is Dependency Injection in Spring Boot?
You can also expect Dependency Injection in Spring Boot interview questions like this.
Dependency Injection is a design pattern used to implement IoC (Inversion of Control). It allows the creation of dependent objects outside of a class and provides those objects to a class in various ways (constructor, setter method, or field injection).
- What are the steps in the Spring Bean Life Cycle?
Apart from Spring Boot, the interviewer may also ask Spring Bean Life Cycle interview questions like this one.
The Spring Bean Life Cycle includes:
- Instantiation: Creating the bean instance.
- Population: Injecting dependencies.
- Initialization: Calling @PostConstruct methods and custom init methods.
- Ready for Use: The bean is now ready to be used.
- Destruction: Calling @PreDestroy methods and custom destroy methods before the bean is removed from the container.
Spring Boot Interview Questions for Experienced
Here are some Core Spring interview questions and their answers for experienced candidates.
Spring Boot Interview Questions for 2-Year Experienced Candidates
- What is the main advantage of using Spring Boot?
The main advantage of using Spring Boot is that it simplifies the setup and development of Spring applications by providing default configurations and reducing boilerplate code.
- How do you create a simple Spring Boot application?
To create a simple Spring Boot application, you can use Spring Initializr to generate a project with the necessary dependencies. Then, you can build and run the application using an embedded server like Tomcat or Jetty.
Spring Boot Interview Questions for 3 Years Experienced Candidates
- What is the @RestController annotation used in Spring Boot?
The @RestController annotation is used to create RESTful web services using Spring MVC. It combines @Controller and @ResponseBody, eliminating the need to annotate each method with @ResponseBody.
- How do you configure logging in a Spring Boot application?
Logging in a Spring Boot application can be configured using the application.properties file. You can specify logging levels, appenders, and log formats in this file.
Spring Boot Interview Questions for 5 Years Experienced Candidates
- What is the role of embedded servers in Spring Boot?
Embedded servers in Spring Boot allow you to run your application as a standalone JAR file without needing to deploy it to a separate web server. Examples of embedded servers include Tomcat, Jetty, and Undertow.
- How does Spring Boot support externalized configuration?
Spring Boot supports externalized configuration by allowing you to define application properties outside of your code. You can use property files, environment variables, or command-line arguments to configure your Spring Boot application.
Spring Boot Interview Questions for 7 Years Experienced Candidates
- What is a Spring Boot Actuator?
Spring Boot Actuator is a sub-project of Spring Boot that provides production-ready features to help you monitor and manage your application. It includes built-in endpoints for metrics, health checks, and other useful information.
- How do you handle exceptions in a Spring Boot application?
In a Spring Boot application, you can handle exceptions using @ExceptionHandler methods. These methods are annotated with @ExceptionHandler and can be defined in a controller to handle specific exceptions thrown by the application.
Also Read - Top 25 Exception Handling Questions In Java Interview
Spring Boot Interview Questions for 10 Years Experienced Candidates
Here are some important Spring interview questions for candidates with 10 years of experience.
- What is Spring Boot Auto-Configuration?
Spring Boot Auto-Configuration automatically configures your Spring application based on the dependencies you have added to the classpath. It eliminates the need for manual configuration in many cases, making development faster and more convenient.
- How do you deploy a Spring Boot application to a production environment?
To deploy a Spring Boot application to a production environment, you can build an executable JAR file using the mvn package or ./gradlew build command. Then, you can run the JAR file on your production server using the java -jar command.
- Have you ever led a team in the development of a complex Spring Boot project? How did you ensure the project’s success?
“Yes, I have. As the leader of a team working on a complex Spring Boot project, I made sure everyone understood their tasks and deadlines clearly. I checked the code regularly to keep its quality high and helped team members when they needed it.
By making sure we all talked openly, worked together, and followed best practices, we finished the project on time and within our budget.”
Spring Framework Java Interview Questions
Here are some important Spring Framework interview questions and their answers.
- What is the purpose of Spring Security?
This is one of the most common Spring Security interview questions.
The purpose of Spring Security is to provide authentication, authorization, and protection against common security attacks such as CSRF and XSS in Spring-based Java applications.
- How do you configure authentication in Spring Security?
Authentication in Spring Security can be configured using WebSecurityConfigurerAdapter to define authentication rules, user details, and password encoding.
- What are the main components of Spring Cloud?
You may also encounter Spring Cloud interview questions like this one.
The main components of Spring Cloud include service discovery, configuration management, circuit breakers, intelligent routing, and load balancing.
- What is the purpose of AOP in Spring?
This is one of the most important Spring AOP interview questions.
The purpose of Aspect-Oriented Programming (AOP) in Spring is to separate cross-cutting concerns from the main application logic. It allows for the declarative application of concerns such as logging, transaction management, and security across the application.
- What is the difference between Spring Web MVC and Spring WebFlux?
Here’s how you should answer such Spring WebFlux interview questions.
Spring Web MVC is a traditional blocking framework for building web applications, while Spring WebFlux is a non-blocking reactive framework. Spring WebFlux uses Project Reactor to handle asynchronous and event-driven programming.
Also Read - Top 10 Most Popular Programming Languages of the Future
Spring Boot REST API Interview Questions
Now let’s take a look at some commonly asked Spring Boot REST API interview questions and their answers.
- What is a REST API, and how does Spring Boot support RESTful web services?
This is one of the most common Spring REST API interview questions.
A REST API (Representational State Transfer) is a set of rules that allows for interaction between applications using HTTP methods. Spring Boot simplifies the creation of RESTful web services by providing annotations like @RestController and @RequestMapping, which make it easy to map HTTP requests to specific methods in your application.
- How do you secure a Spring Boot REST API using OAuth2?
You can expect OAuth2 Spring Boot interview questions as well. This is a common question.
Spring Boot integrates with OAuth2 to secure REST APIs by using Spring Security OAuth2. You can configure OAuth2 by adding the necessary dependencies and defining client credentials, resource server settings, and token management in your application properties. The @EnableOAuth2Client and @EnableResourceServer annotations help manage OAuth2 tokens and secure endpoints.
- What are the key components of Spring Security OAuth2 in securing REST APIs?
You might also come across Spring Security OAuth2 interview questions like this one.
The key components include:
- Authorization Server: Responsible for generating tokens.
- Resource Server: Protects the REST API resources and validates tokens.
- Client: The application that requests access tokens to interact with the protected resources.
- Tokens: Access tokens and refresh tokens are used to access secured resources.
- How do you handle versioning in a Spring Boot REST API?
Spring Boot API interview questions often include topics about handling versioning. This is how you should answer it.
Versioning in a Spring Boot REST API can be handled in several ways:
- URI Versioning: Include the version in the URI, e.g., /api/v1/resource.
- Request Parameter Versioning: Use a request parameter, e.g., /api/resource?version=1.
- Header Versioning: Include the version in the request headers, e.g., X-API-Version: 1.
- Content Negotiation Versioning: Use the Accept header to specify the version, e.g., Accept: application/vnd.company.v1+json.
- How do you handle JSON responses in Spring Boot REST APIs?
This is another one from the list of important Spring REST interview questions that you may be asked.
In Spring Boot REST APIs, JSON responses are typically handled using the @RestController annotation, which automatically converts Java objects to JSON format using the Jackson library. You can customize the JSON output by using annotations like @JsonProperty to rename fields, @JsonIgnore to exclude fields, and @JsonFormat to format date and time values. This makes it easy to manage JSON responses directly from your Spring Boot application.
Spring WebFlux Interview Questions
Here are some important Spring WebFlux interview questions and their answers.
- How does Spring WebFlux handle error management compared to Spring MVC?
This is one of the most important Spring WebFlux interview questions.
In Spring WebFlux, error handling is done using reactive types such as Mono and Flux. You can use onErrorResume or onErrorReturn to handle errors in a non-blocking way, providing fallback responses or alternative processing. In contrast, Spring MVC handles errors using traditional @ExceptionHandler methods and the HandlerExceptionResolver interface, which are blocking and synchronous.
- What are the advantages of using WebClient in Spring WebFlux?
WebClient is the non-blocking, reactive alternative to RestTemplate in Spring WebFlux. It allows for asynchronous and reactive HTTP requests and supports both synchronous and asynchronous operations. WebClient is more flexible and powerful, especially when dealing with streaming data, large-scale microservices, or scenarios requiring high concurrency.
Spring AOP Interview Questions
Here are some commonly asked Spring AOP interview questions and their answers.
- What is Spring AOP, and how does it differ from AspectJ?
You may come across Spring Boot AOP interview questions like this one.
Spring AOP (Aspect-Oriented Programming) is a part of the Spring Framework that provides support for aspect-oriented programming. Unlike AspectJ, which is a complete AOP framework that provides compile-time and load-time weaving, Spring AOP is proxy-based and only supports runtime weaving. This makes Spring AOP simpler but less powerful compared to AspectJ.
- What are the different types of advice in Spring AOP?
In Spring AOP, advice is the action taken by an aspect at a particular join point. There are five types of advice:
- Before advice: Runs before the method execution.
- After advice: Runs after the method execution, regardless of its outcome.
- After returning advice: Runs after the method returns successfully.
- After throwing advice: Runs after the method throws an exception.
- Around advice: Surrounds the method execution, allowing you to control when the method is called.
Spring Security Interview Questions
Here are some important Spring Security interview questions and their answers.
- How do you integrate Spring Security with Spring Boot?
This is one of the most commonly asked Spring Boot Security interview questions.
Spring Security is integrated with Spring Boot by including the spring-boot-starter-security dependency. This automatically secures all endpoints with default settings, which can be customized by creating a WebSecurityConfigurerAdapter class or a SecurityFilterChain bean.
- What is the purpose of Spring Security’s @PreAuthorize annotation?
The @PreAuthorize annotation is used to restrict method access based on roles or permissions. It allows you to define access control rules at the method level using SpEL (Spring Expression Language), ensuring that only users with the specified roles or conditions can execute the annotated methods.
- How do you implement JWT-based authentication in Spring Boot?
You may also come across Spring Security JWT interview questions like this one.
Implement JWT authentication by adding spring-boot-starter-security and jjwt dependencies. Generate JWT tokens upon successful login, then use a filter to validate these tokens on subsequent requests. This ensures that authenticated users can access secured endpoints.
This is how you should answer about Spring Security in Spring Boot interview questions.
Spring MVC Framework Interview Questions
Here are some of the most common Spring MVC interview questions and their answers.
- What is Spring MVC?
Spring MVC (Model-View-Controller) is a Java web framework built on top of the Spring Framework. It provides a powerful way to build dynamic web applications by separating the concerns of the application into three main components: Model, View, and Controller.
- What are the main components of Spring MVC architecture?
The main components of Spring MVC architecture are:
- Model: Represents the application’s data and business logic.
- View: Represents the presentation layer of the application, typically generated by JSP, Thymeleaf, or other templating engines.
- Controller: Handles incoming requests, processes user input, and interacts with the model to generate an appropriate response.
- How does the DispatcherServlet work in Spring MVC?
The DispatcherServlet is the front controller in Spring MVC that receives all incoming requests and dispatches them to the appropriate controllers based on the request URL.
It also manages the flow of the request processing, including handling exceptions, rendering views, and managing application context.
Also Read - Top 20+ Interview Questions On Java Servlets
Accenture Spring Boot Interview Questions
These are some important Spring Boot interview questions you may encounter at Accenture.
- How would you use Spring Boot to improve the development process at Accenture?
“I would use Spring Boot to make development faster and easier at Accenture by taking advantage of its auto-configuration feature, which sets up the project with minimal setup. The embedded server lets us run applications without needing a separate server, simplifying testing and deployment.
Additionally, using Spring Boot’s externalized configuration helps manage settings for different environments, making the application more flexible and easier to maintain.”
- Can you explain how you handled different client environments using Spring Boot’s externalized configuration, which is similar to what you might do at Accenture?
“In a past project, I managed different client environments using Spring Boot’s externalized configuration by creating separate application.properties files for development, testing, and production. I used Spring Profiles to easily switch between these configurations based on the environment.
This approach allowed for easy management of settings like database connections and API endpoints without changing the application code, which is useful for managing multiple client environments at Accenture.”
Infosys Spring Boot Interview Questions
Here are some common Infosys Java Spring Boot interview questions and their answers.
- How would you integrate Spring Boot with a relational database in a project at Infosys?
“To integrate Spring Boot with a relational database at Infosys, I would use Spring Data JPA. First, I would add the necessary dependencies in the pom.xml file. Then, I would configure the database connection properties in the application.properties file, such as the URL, username, and password.
I would create entity classes mapped to database tables and repository interfaces to handle CRUD operations. Spring Data JPA simplifies data access and provides an easy way to interact with the database.”
- Can you explain how you would use Spring Boot to build a RESTful API for an Infosys project?
“To build a RESTful API using Spring Boot for an Infosys project, I would start by creating a Spring Boot application with the necessary dependencies for web support. I would then define controller classes annotated with @RestController to handle HTTP requests.
Each method in the controller would be mapped to specific URLs using the @RequestMapping or @GetMapping, @PostMapping, @PutMapping, and @DeleteMapping annotations. The controller methods would process requests, interact with the service layer, and return responses in JSON or XML format.”
This is how an Infosys certified Spring Boot developer answers these questions.
Spring Boot Coding Interview Questions
Here are some important Spring Programming interview questions and their answers.
- How do you handle exceptions in a Spring Boot application?
To handle exceptions in a Spring Boot application, you can use the @ControllerAdvice and @ExceptionHandler annotations. Create a class annotated with @ControllerAdvice to handle exceptions globally.
@ControllerAdvice
public class GlobalExceptionHandler {
@ExceptionHandler(ResourceNotFoundException.class)
public ResponseEntity<String> handleResourceNotFoundException(ResourceNotFoundException ex) {
return new ResponseEntity<>(ex.getMessage(), HttpStatus.NOT_FOUND);
}
@ExceptionHandler(Exception.class)
public ResponseEntity<String> handleException(Exception ex) {
return new ResponseEntity<>(ex.getMessage(), HttpStatus.INTERNAL_SERVER_ERROR);
}
}
- How do you handle form submissions in a Spring Boot application?
To handle form submissions in a Spring Boot application, you can use @PostMapping and bind the form data to a model object using @ModelAttribute.
Here’s an example:
@Controller
public class UserController {
@GetMapping(“/form”)
public String showForm(Model model) {
model.addAttribute(“user”, new User());
return “form”;
}
@PostMapping(“/form”)
public String submitForm(@ModelAttribute User user, Model model) {
model.addAttribute(“user”, user);
return “result”;
}
}
class User {
private String name;
private String email;
// Getters and setters
}
- How do you schedule tasks in a Spring Boot application?
To schedule tasks in a Spring Boot application, you can use the @Scheduled annotation along with @EnableScheduling in your configuration class.
Here’s an example:
@Configuration
@EnableScheduling
public class SchedulingConfig {
}
@Component
public class ScheduledTasks {
@Scheduled(fixedRate = 5000)
public void reportCurrentTime() {
System.out.println(“Current time: ” + new Date());
}
}
Also Read - Top 25+ Interview Questions On String in Java with Answers
Spring Boot MCQs
You may also come across MCQs during the interview. Here are some common Java Spring Boot interview questions in MCQ form.
- What is the default embedded server used in Spring Boot?
A. Jetty
B. Tomcat
C. Undertow
D. WildFly
Answer: B. Tomcat
- Which annotation is used to enable Spring Boot auto-configuration?
A. @SpringBootApplication
B. @EnableAutoConfiguration
C. @Configuration
D. @ComponentScan
Answer: B. @EnableAutoConfiguration
- Which of the following is NOT a valid way to run a Spring Boot application?
A. Using java -jar command
B. Running the main method in the @SpringBootApplication class
C. Deploying as a WAR file to an external server
D. Using a javac command
Answer: D. Using a javac command
- Which dependency do you need to add to your pom.xml to use Spring Boot with Thymeleaf?
A. spring-boot-starter-thymeleaf
B. spring-boot-starter-web
C. spring-boot-starter-data-jpa
D. spring-boot-starter-freemarker
Answer: A. spring-boot-starter-thymeleaf
- What is the purpose of the spring-boot-starter-parent in a Spring Boot application?
A. To provide default configurations for Maven build
B. To enable Spring Boot auto-configuration
C. To define the main class of the application
D. To specify application properties
Answer: A. To provide default configurations for Maven build
Also Read - Top 25+ Frontend Interview Questions and Answers
Wrapping Up
And that’s a wrap!
These are the 50+ most commonly asked Spring Boot interview questions along with their answers. We’ve covered various aspects, from basic concepts to advanced topics, to help you prepare confidently for your interview. And if you are still on the hunt for a spring boot job, head over to Hirist. It’s one of the best job portals to find the latest and best tech jobs in India. Connect with over 50,000 recruiters from top IT firms and land your dream job with Hirist!
Note: Change the list of interview questions from 40 to 50+ in the meta title and meta description.
