Spring Boot Interview Questions and Answers

Ques 1. What is DevTools in Spring Boot?

Spring Boot DevTools helps you to increase the productivity of the developer. So, you do not require to redeploy your application every time you make the changes. It allows the developer to reload changes without the need of restarting of the server.

Ques 2. What are the essential components of Spring Boot?

Ques 3. What is spring-boot-starter-parent?

It is a special starter which makes Gradle or Maven dependency-management easy by adding jars to your classpath.

Ques 4. How to enable HTTP/2 supports in Spring Boot?

Ques 5. What is a Spring Boot Actuator?

Spring Boot Actuator allows you to monitor and manage your application when you want to push it for the production. It helps you to control your application by using HTTP endpoints.

Ques 6. Explain Spring Boot Admin.

Spring Boot admin is a community project which helps you to manage and monitor your Spring Boot applications.

Ques 7. Explain Spring CLI.

Spring CLI is used for writing in Groovy Spring Boot application, which helps you to concise code.

Ques 8. What are embedded containers support by Spring?

Ques 9. Explain thymeleaf in Spring Boot.

Thymelaf is a server-side Java template engine for a web application. It helps you to bring elegant natural templates to your web application.

Ques 10. What is a shutdown in the actuator?

Ques 11. Is it possible to replace or override the Embedded Tomcat server in Spring Boot?

Yes, it is possible to replace the Embedded Tomcat with any other servers by using the starter dependencies. For that, you can use spring-boot-starter-jetty or as a dependency for according you to your need.

Ques 12. Can you disable the default web server in the Spring Boot application?

Yes, we can disable the default web server by using application.properties to configure the web application type.

Ques 13. How do you Add, Filter to an application?

Ques 14. What is the use of profiles in Spring Boot?

Profiles are used to separate various parts of your spring application configuration and make it only available in certain environments.

Ques 15. What is LiveReload in Spring Boot?

LiveReload is a spring-boot-devtools module that includes LiveReload server to trigger a browser refresh when a resource is changed. LiveReload server extensions are available freeware for Firefox, Chrome, and Safari.

Ques 16. What are the major benefits of spring Externalized Configuration?

Externalized Configuration helps to work with the same code in different environments. Developers can use YAML files, properties files, command-line arguments, and environment variables to externalize configuration.

Ques 17. What do you mean by hot-swapping in Spring Boot?

It is a way to reload the changes without restarting Tomcat, or Jetty server. Eclipse and Many other IDEs support bytecode hot swapping. If you make any changes that don’t affect the method signature, it should reload without side effect.

Ques 18. How to handle exception in Spring Boot.

Spring Boot provides a very useful way to handle exceptions using @ControllerAdvice annotation.

Ques 19. What is mean by spring batch?

Spring Boot Batch provides code reusability which is important when working with large numbers of records, including transaction management, logging, skipping, job processing statistics, and job restarts.

Ques 20. Explain CORS in Spring Boot?

CORS stands for Cross-Origin Resource Sharing is a  mechanism implemented by browsers and helps users to authorize cross-domain requests. This mechanism serves as an alternative to less secure and less powerful hacks of the kinds of IFrame or JSONP.

Ques 21. How can you set active profile in Spring Boot?

Ques 22. List out some of the Spring Boot Starters.