Spring Boot Interview Questions

What is Spring Boot?

Spring Boot is one of the Spring modules providing RAD(Rapid Application Development) functionality.
We can develop standalone spring based applications that you can just run because it needs very little spring configuration.

What are the advantages of spring boot?

It helps you to develop stand-alone application which can be started using java.jar file.
It offers pinpointed ‘started’ POMs to Maven configuration.
It allows you to Embed Undertow, Tomcat, or Jetty directly.
It helps you to configure spring whenever possible automatically.

What are the Spring boot annotations?

What are the features of Spring boot?

Commands used to run and stop Spring Boot executable jar file?

What is Spring Boot starter? How is it useful?

Spring Boot has many starters.
They are a set of convenient dependency descriptors.
Starter allows you to include these descriptors in your pom.xml.
If you want to work with Spring MVC, you can include “spring–boot–starter–web” as a dependency in pom.xml

What is the configuration file name in spring boot?

The configuration file used in Spring Boot projects is called “application.properties”.
It is an important file which allows you to override your default configurations.

What is DevTools in Spring Boot?

Spring Boot DevTools helps you to increase the productivity of the developer.
So, you don’t require re-deploying your application every time you make the changes.
It allows the developer to reload changes without the need of restarting of the server.

What are the Components of Spring Boot?

What is 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.

What is Spring Boot Initilizr?

Spring Boot Initilizr is a Spring Boot tool to bootstrap Spring Boot or Spring Applications very easily.
Forms are:
- Spring Boot Initilizr With Web Interface
- Spring Boot Initilizr With IDEs/IDE Plugins
- Spring Boot Initilizr With Spring Boot CLI
- Spring Boot Initilizr With ThirdParty Tools

What is Spring Batch? How do you implement it using Spring Boot?

Spring Boot Batch provides reusable functions that are essential in processing large volumes of records, including logging/tracing, transaction management, and job processing statistics, job restart, skip, and resource management.
It also provides more advanced technical services and features that will enable extremely high-volume and high performance batch jobs though optimization and partitioning techniques.

What is FreeMarker Template?

FreeMarker is a Java-based Template Engine, originally focusing on dynamic web page generation with MVC software architecture.
The major advantage of using Freemarker is the complete separation of the Presentation layer and the Business Layer.

What is Starter dependency?

This feature aggregates common dependencies together.
For example, if you want to develop Spring MVC based RESTful services then instead of including Spring MVC JAR and Jackson JAR file into classpath you can just specify spring-boot-web-starter and it will automatically download both those JAR files.
Spring Boot comes with many such starter dependencies to improve productivity.

What is Auto-Configuration?

This is another awesome feature of Spring Boot which can configure many things for you.
For example, If you are developing Spring web application and Thymeleaf.jar is present on the classpath then it can automatically configure Thymeleaf template resolver, view resolver, and other settings.
A good knowledge of auto-configuration is required to become experienced Spring Boot developers.

What is Spring CLI?

This is another awesome feature of Spring Boot which really takes Spring development into next level.
It allows you to use Groovy for writing Spring boot application which means a lot more concise code.

How do you implement FreeMarker template using Spring Boot?

The Programmers can work on the application code while the designers can work on the html page design.
Finally using freemarker these can then be combined to give the final output page.

How to implement Exception Handling using Spring Boot?

Spring provides a very useful way to handle exceptions using ControllerAdvice.
We will be implementing a ControlerAdvice class which will handle all exceptions thrown by the controller class.

What is AOP? How to use it with Spring Boot?

During software development, functions that span multiple points of an application are called cross-cutting concerns.
These cross-cutting concerns differ from the applications main business logic.
Separating these cross-cutting concerns from the business logic is where aspect-oriented programming (AOP) comes into picture.

What is Apache Kafka? How to integrate it with Spring Boot?

Apache Kafka is a distributed publish-subscribe messaging system.
It is a scalable, fault-tolerant, publish-subscribe messaging system which enables us to build distributed applications.
It is an Apache Top Level project. Kafka is suitable for both offline and online message consumption.

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