Spring Boot is a popular Java framework for creating stand-alone, production-grade applications. Spring Boot makes it easy to create a Spring-based application that you can “just run”. However, as with any technology, there are some key concepts that you need to understand before starting to use it. This blog post will help you get up to speed with Spring Boot quickly by answering 30 of the most commonly asked spring boot interview questions. By the end of this post, you’ll be ready for your next job interview!
If you’re reading this post, then congratulations – you’ve made the first step on your journey to becoming a Java programmer! In this blog post, we’ll take a look at 30 of the most commonly asked interview questions for 2 to 3 years of experience.
Spring Boot Interview Questions For Beginners:
Ques 1- What is Spring Boot?
Ans- Spring Boot makes it easy to create stand-alone, production-grade Spring applications. We take an in-depth view of the Spring platform and third-party libraries so you can get started with minimum fuss. Most Spring Boot applications need very little Spring configuration.
Ques 2- What are some important features of Spring Boot?
Ans- Some of the important features are listed below:
- Ability to add third-party libraries quickly and easily.
- Provides support for testing frameworks such as JUnit, Mockito, Powermock, etc. out of the box.
Ques 3- What is the latest version of Spring Boot?
Ans- The latest version of Spring Boot is 1.5.2. Before this, the latest version was 1.5.1.
Ques 4- What are the advantages of Spring Boot over traditional Spring applications?
Ans- Some important advantages are listed below:
- Traditional Spring applications tend to have a lot of XML configuration, which in turn makes them a little difficult to understand and maintain. Spring Boot helps you in avoiding this by autoconfiguring your application so that you don’t have to provide any configuration details manually.
- Traditional Spring applications require a lot of time for building and deployment even for the most trivial of changes. In contrast, Spring Boot applications are built really quickly.
Ques 5- How does Spring Boot help in faster development?
Ans- Some important features that help with faster development in Spring Boot include:
- Spring Boot provides the ability to add third-party jar files without having to explicitly specify them in the build configuration. All you need to do is add a particular dependency in your Maven POM and Spring Boot takes care of the rest.
- Spring Boot comes with a built-in ‘Developer tools’ feature. This allows you to run your application using an interactive console and see the value of any variables at runtime without having to recompile/redeploy your application.
Ques 6- What is Spring Boot used for?
Ans- Spring Boot is used in many different kinds of projects, from building microservices to creating web applications.
Ques 7- How do you create a web application using Spring Boot?
Ans- One of the quickest ways to get started is by developing a ‘Reactive RESTful Web Service’ application. This type of application allows you to create a REST API easily and has built-in support for creating WebSocket-based web applications.
Ques 8- How do you create a microservice using Spring Boot?
Ans- The quickest way to get started with Spring Boot is by developing a ‘Feign REST Client application. This type of application allows you to reduce the boilerplate code required for creating your REST API client and take advantage of Spring Boot’s built-in features such as autoconfiguration and ‘Developer tools.
Ques 9- What is the Spring Framework?
Ans- The Spring Framework is a framework used to build Java applications. It provides lots of useful features related to object-relational mapping, data access, and transactions management, rather than low-level implementation details.
Ques 10- How does Spring Boot compare to traditional spring applications?
Ans- The biggest advantage of using Spring Boot over traditional spring applications is the ‘automatic configuration’. This means that you can get started with very little or no configurations and add extra dependencies/configurations as required only at the time of development.
Spring Boot Interview Questions For Experienced
Ques 11- How can you run a spring boot application?
Ans- The easiest way to run a Spring Boot application is by using the Spring Boot ‘Starter’ project template. If your pom.xml file for your Maven POM project contains the necessary dependencies, then all you need to do is type in mvn spring-boot:run at the command line and your application starts up instantly.
Ques 12- What is Spring Boot Actuator?
Ans- Spring Boot actuator comes as a part of the Spring Boot starter project template. It provides useful information such as the health of your application, resource usage, etc. on an interface that can be accessed through a local web browser or from remote applications even over the web.
Ques 13- What is the difference between a ‘Starter’ and a ‘Spring Boot Starter’?
Ans- A spring boot starter project template is a set of template files that allow you to create a spring-boot application quickly without having to provide lots of information manually. A single starter can provide multiple types of functionality depending on how it’s configured. For example, the spring boot actuator starter provides a way to access information about your application using a local web browser or from remote applications even over the web.
Ques 14- What is Spring Initializr?
Ans- Spring Initializr is an online tool that was created by Pivotal as a means of creating ‘Starter’ project templates for the spring platform. The process of creating a ‘Starter’ project template from Spring Initializr is very simple and can be completed in a few minutes.
Ques 15- What are the steps to add your own maven repository?
Ans- The first step is to add a Maven local repository definition file called ‘settings.xml’. This file should live at the top level of your project folder. Once this is done, you can add any additional repositories to your ‘settings.xml’ file as required by adding entries for each repository URL and groupId/artifactId details.
Ques 16- What are Spring Boot Starters?
Ans- A Spring Boot starter provides all the dependencies that are required for a particular type of functionality. For example, the spring boot actuator starter provides all the dependencies required to access information about your application using a local web browser or from remote applications even over the web.
Ques 17- What are Spring Boot Auto-configured Starter Projects?
Ans- Spring Boot auto-configured starter projects provide lots of functionality out of the box and in effect make your job of creating a Spring Boot application even easier.
Ques 18- How do you add dependencies to a pom file?
Ans- To add dependencies to a Maven POM file, just add entries to the dependencies section of the pom file.
Ques 19- What are Spring Boot Actuator endpoints?
Ans- Spring Boot Actuator endpoints provide the ability to access information about your application using a local web browser or from remote applications even over the web.
Ques 20- What is a Dashboard in Spring Boot Actuator?
Ans- The dashboard feature provides a convenient way to monitor your application using a local web browser by rendering various graphs and charts based on the information available from the underlying beans. Once a dashboard is enabled, a link to the dashboard page appears in the local development environment’s main navigation menu under “info”.
Ques 21- What is a web endpoint in Spring Boot?
Ans- A web endpoint is an actuator endpoint that enables you access to its functionality even from remote applications or over the web.
Spring Boot Tricky Interview Questions And Answers:
Ques 22- What is the difference between Spring Boot and Spring Cloud?
Ans- The spring cloud project aims to make it easier for Java developers to create microservice-based applications. It provides a wide range of libraries that are used in today’s highly distributed architectures. Therefore, if your application needs to communicate with other services or applications over the network, you can use Spring Cloud to make the necessary calls.
Ques 23- What are Spring Boot Devtools?
Ans- Spring Boot Devtools is a tool that can be configured to automatically recompile and reload your application whenever you save changes in your project source files. It offers out-of-the-box support for Jetty, Tomcat, Undertow, and vertx web frameworks.
Ques 24- What are Spring Boot Actuator Metrics?
Ans- Spring boot actuator metrics provide the ability to monitor various system-level metric information about your application including memory usage, thread counts, response times, etc. Monitoring various metrics about your application based on different criteria is an important part of understanding how well your application is performing in production. Metrics are typically captured by adding the Spring Actuator library to your application and configuring different metric reporters for collecting system-level metric information about your application.
Ques 25- Which web framework does Spring Boot use?
Ans- Spring boot has the option of using either Jetty or Tomcat as its default embedded servlet container that is used to run your Spring Boot applications.
Ques 26- How do you add dependencies to a maven pom file?
Ans- To add dependencies to a Maven POM file, just add entries to the dependencies section of the pom file.
Ques 27- What are Actuator Endpoints?
Ans- Actuator endpoints provide the ability to access information about your application using a local web browser or from remote applications even over the web. Actuator endpoints can either be secured or unsecured depending on how you configure your spring boot project.
Ques 28- What are the steps for creating a REST server using Spring Boot?
Ans- The following are the steps for creating a REST server using Spring boot.
- Create an Application class by extending the SpringBootApplication class
- Add configuration settings to your application properties
- Register any HTTP endpoints in your Application
- Run your Application as a standalone executable JAR or inside a servlet container.
Ques 29- How can you run a Spring Boot app as a standalone executable jar file?
Ans- A spring boot application can be started either by running the jar from the command line or by using an IDE such as an eclipse. To run the spring boot application on the command line, all you need to do is build your project and use the java -jar maven plugin to run your jar file.
Ques 30- What are some of the best practices to use with Spring Boot?
Ans- The following are some of the best practices to use with Spring Boot.
- 1. Keep your application package name lowercase
- Do not hard code configuration settings in your application
- Prefer using an external config server for storing configuration
- Use environment variables instead of hard-coded values in your application.
Spring Boot is a powerful Java framework that makes it easy to create microservice-based applications. It provides a wide range of libraries that are used in today’s highly distributed architectures. In this article, we’ve provided 30 spring boot interview questions for 2 to 3 years of experience. We hope you find these questions and answers helpful as you prepare for your next job interview.
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