Spring Boot interview questions and answers

Spring Boot interview questions are helpful for a Java Developer to start his career. Everyone should take preparation for a job interview. It is an essential step for them. So, prepare yourself as a professional one.

Then search for the most asked questions available on the internet for interviews. However, Spring Boot is a popular technology in Java programming. It is used to develop web applications. This java framework is now used widely. I have collected some common and frequently asked questions on Spring Boot. Let’s have a look at preparing yourself for your next interviews. 

What is the spring boot interview questions?

Spring Boot is a java framework. People use it to create web applications. When you go through an interview. You may feel nervous. But when you go through good preparation. You may get confident.

Now Spring Boot development is a demanding job for Java developers. With this framework, developers can build quick but advanced applications to the web system. However, it would be best to take an idea. Spring Boot interview questions before your interview. Learn about the features, project, venture. Applications, properties, actuators, and other sides of Spring Boot. Then face the interview with confidence. 

Spring Boot interview questions

Some Spring Boot interview questions are described below. These questions will help you to understand a lot about Spring Boot.

What is the difference between Spring and spring boot?

Spring is a Java-based web application framework. It contains tools to make a web application. On the other hand, Spring Boot takes the application development to the next level with Spring. It removes all the difficulties. Thus it makes the application easy to maintain. So, Spring is a little bit complex than Spring Boot. 

What are the benefits of spring boot interview questions?

Some benefits of Spring Boot are here:

• The auto-configuration feature of Spring Boot loads some default forms. Besides, it helps to start the application quickly. 
• Spring Boot allows the developers to create applications with a lot of features. So, Spring Boot is better for large projects.
• Spring Boot makes the configurations easy. It also lessens the effort of developers.
• It reduces the time of application development.
• You can test the applications and develop them with the CLI tool.
• Besides, it confirms dependency management. It also provides some security metrics.
• Spring Boot has many APIs to monitor and maintain web applications.

What are the drawbacks of Spring Boot?

The most common disadvantage of Spring Boot is its lack of control. Extra dependencies also increase the file size of deployment. Having some useful tools. These are not enough. Besides, it doesn’t seem easy to update the Spring code. You need more experience to work with Spring Boot. For microservers, it is quite good. But I recommend you to start with Spring Boot after learning it properly.

Describe some features of Spring Boot.

Nowadays, the Spring Boot framework is essential for apps development. It comes with auto-configuration and server support. Thus it becomes the popular technology in the Java ecosystem. Now see the main features of this framework.

Starter dependency

There are some dependencies available in Spring Boot. Some of them are Web and Web Starters. So, when you use Spring or JPA to access the database. You can use starter dependency. 

Spring Initializr

It is an application for the web that makes the project set up quickly. The reason is that it builds scripts and creates its initial structure. It also reduces development time and increases productivity.

Auto-Configuration

Auto-configuration is another feature of Spring Boot. It scans the classpath. Besides, it searches the libraries’ in the classpath. It also provides the required form to start the app. When you develop an app with this programming, you can use a Thymeleaf.jar in the classpath. Then it will align the Thymeleaf settings automatically.

Spring Actuator

Spring Actuator is very helpful for microservices. It comes with some features like auditing, log data, etc. Besides, it has its command endpoints, which are secured enough. 

How to create a Spring Boot application with Maven?

There are many approaches to make a Spring Boot application with Maven. Among them, you can follow the ways below using Maven.

• Spring Boot CLI
• Spring Initializer
• Maven Project

Explain what is Spring Actuator and what are its benefits

Spring Actuator is available in Spring Boot. With this feature, you can monitor the inside of a running application. If you want to debug an app, you need Spring Actuator. Besides, it helps to analyze the application to understand. With actuators, you can easily access knowing beans and CPU usage. Similarly, you can quickly access the REST points with this feature. Moreover, get essential information from the website. 

What is Spring Initializr?

Though it a difficult one among Spring Boot interview questions, the interviewers can ask it to check a candidate’s knowledge. Spring Initializr is a way or web application that helps to create a Spring Boot project initially. That means it allows us to make the structure of the task properly. The simple way is to go to a Spring Initializr site. Then choose the dependency tool like Maven and select a language like Java. Now take a packing scheme, dependencies, and then download your Spring Boot project. 

What do you mean by starter dependency, and how does it works?

It is a follow-up question because it is similar to auto-configuration. So, many people get confused about them. Starter dependency works for dependency management. After working with some spring projects, you may notice that some libraries are used to create REST web services. Making dependency on pom.xml is difficult. But it combines some libraries into one functionality to create a starter package. 

So, starter dependency saves time. It also makes our work easier. It pulls some libraries automatically. Thus it keeps you free from compatibility issues.

What do you mean by Spring Boot CLI, and what are the benefits of it?

It is one type of command line for creating a java app based on Spring using Groovy. So, without using the ceremony, e.g., make an application from this command-line. And you can avoid modifiers and return reports for your application. 

Besides, it is a powerful option that can include libraries in the default package of Groovy.

What are the possible sources of external form in Spring Boot?

It is another essential Spring Boot interview question. Of course, Spring Boot allows you to run an application in many situations. You can do it for the support that it gives you for external configuration. However, to do this, Spring Boot uses properties files, YAML files, environment variables, command-line, etc. These indicate the configuration properties. Besides, Spring Boot uses @value annotation to get access to the required properties. Now, See the possible sources below:

• Application properties: To load application properties. Spring Boot looks out for those properties or YAML files in classpath. Configuration directory, or current directory.
• Command-line: Command line arguments are converted to properties by Spring Boot. Then these properties are added as environment properties. 
• Profile-specific properties: These are the properties that are from the YAML file of the application. 

Why do you need spring boot interview questions DevTools?

Spring Boot DevTools is a set of tools. It helps to build an application on Spring Boot quickly. At the time of running an application. The developer tools are automatically disabled. Besides, archives repackaging also eliminated. So, it would help if you had developer tools. To reach properties to particular environments. For this, add the dependency into the pom.xml file. It will include the Developer Tools.

Describe the required steps to build the spring boot interview questions project with Spring Initializr.

Spring Initializr is a tool of Spring. It helps the developer to create a Spring Boot project. Now see the steps of creating a project with Spring Boot using this web tool.

At first, you have to select the necessary dependencies and Maven the project. Then collect the other details such as Group, Artifact. Now generate the project.

After downloading the project, extract it onto the system.

Now use the import option to import your project on Spring Tool Suite IDE. 

But during this work, choose the type of your project as Maven. However, the source project must contain a pom.xml file. 

If you follow the above steps carefully. You may find that your Spring Boot project is ready. It also comes with the necessary dependencies.

How do you enable hot deployment or live to reload on a browser?

Most of the recent IDEs support hot deployment. Besides, it allows us to reload changed codes without any side effects. Moreover, the Devtools of Spring Boot allows automatic restarts when any file on the classpath changes.

However, a new entry on the classpath that comes to a folder is observed for changes. But some resources can work without restarting the application. An example is view templates.

Devtools module has a LiveReload server. It refreshes the browser when any resource is modified. However, this extension is available for free for browsers like Chrome and Firefox. Get it from livereload.com.

So, to enable or disable LiveReload, you have to change the “spring.devtools.livereload.” enabled value to the default value.

Why you use @RequestMapping in spring boot interview questions?

To run routing information, we use @RequestMapping annotation. 

How can you deploy Spring Boot applications as Jar or War files?

Generally, we set a web application in the form of a WAR file. Then use it into the external server. It allows us to arrange some applications on a server. When your CPU or memory gets scarce. It is the best way to save your resources. But now the hardware of a computer is cheap.

People are now thinking about server configuration. So, a little mistake in server configuration during deployment can lead to worse consequences. However, spring-boot-maven-plugin is now available to solve this problem. It helps to deploy the web application to an executable JAR.

Which build systems are supported in Spring Boot?

Maven, Gradleare the supported build systems in Spring Boot. They allow dependencies. 

Describe the advantages of spring boot interview questions.

Cloud-based data service, relational and non-relational databases are now manageable because of Spring Data. We see that spring data helps to easy access to all data.

Is it possible to change the embedded Tomcat server port?

Yes, you can change the embedded Tomcat server port. For this, add a service port on the application properties file. It is an automatic file of Spring Boot. Besides, you can use it to configure application code.

What is thyme leaf in spring boot interview questions?

It is a Java template engine. In Spring Boot, you can use it to make an application. Developers use it for natural templates.

How to enable or disable the Actuator in Spring Boot?

It is easy to enable or disable the actuator in Spring Boot. To allow it to add Maven or Gradle to the starter actuator. When you want to disable it, do not add the dependency.

The demand for Spring Boot is increasing with the development of the IT sector. Spring Boot helps to make web applications quickly. So, start an excellent career as a Java Developer. But only understanding Java is not enough. You have to perform better in the interview. I think these Spring Boot interview questions with answers. This are helpful enough for you will help you much to attend job interviews. All of them are fundamental questions. So, go through them to gain a basic idea for an interview.