Top 100+ Spring Boot Interview Questions And Answers
Question 1. What Is Spring Boot?
Answer :
First of all Spring Boot isn't a framework, it is a way to ease to create stand-alone utility with minimal or zero configurations. It is approach to increase spring primarily based utility with very less configuration. It offers defaults for code and annotation configuration to brief start new spring tasks within no time. It leverages current spring tasks as well as Third birthday celebration projects to broaden production geared up applications. It provides a hard and fast of Starter Pom’s or gradle construct files which you'll be able to use to feature required dependencies and additionally facilitate automobile configuration.
Spring Boot robotically configures required lessons depending on the libraries on its classpath. Suppose your application need to interact with DB, if there are Spring Data libraries on class course then it automatically units up connection to DB in conjunction with the Data Source elegance.
Question 2. What Are The Advantages Of Using Spring Boot?
Answer :
It may be very clean to broaden Spring Based packages with Java or Groovy.
It reduces masses of development time and will increase productivity.
It avoids writing masses of boilerplate Code, Annotations and XML Configuration.
It could be very clean to integrate Spring Boot Application with its Spring Ecosystem like Spring JDBC, Spring ORM, Spring Data, Spring Security and so on.
It follows “Opinionated Defaults Configuration” Approach to reduce Developer attempt
It gives Embedded HTTP servers like Tomcat, Jetty etc. To broaden and check our net packages very without problems.
It gives CLI (Command Line Interface) tool to develop and test Spring Boot (Java or Groovy) Applications from command activate very easily and speedy.
It gives plenty of plugins to increase and check Spring Boot Applications very effortlessly using Build Tools like Maven and Gradle
It provides plenty of plugins to paintings with embedded and in-memory Databases very easily.
Adv Java Interview Questions
Question three. What Are The Disadvantages Of Using Spring Boot?
Answer :
It may be very hard and time consuming technique to convert present or legacy Spring Framework initiatives into Spring Boot Applications. It is applicable simplest for trendy/Greenfield Spring Projects.
Question 4. Why Is It “opinionated”?
Answer :
It follows “Opinionated Defaults Configuration” Approach to reduce Developer attempt. Due to opinionated view of spring boot, what is required to get started but also we will get out if now not appropriate for software.
Spring Boot uses realistic defaults, “opinions”, generally based on the classpath contents.
For example
Sets up a JPA Entity Manager Factory if a JPA implementation is on the classpath.
Creates a default Spring MVC setup, if Spring MVC is at the classpath.
Everything may be overridden without problems
But most of the time now not wanted.
Adv Java Tutorial
Question five. How Does It Work? How Does It Know What To Configure?
Answer :
Auto-configuration works by using studying the classpath
If you forget a dependency, Spring Boot can’t configure it
A dependency management tool is recommended
Spring Boot figure and starters make it much simpler
Spring Boot works with Maven, Gradle, Ant/Ivy
Our content here will display Maven.
J2EE Interview Questions
Question 6. How Are Properties Defined? Where?
Answer :
In spring boot, we have to outline houses within the application.Residences document exists in classpath of utility as follow.
Example: configure default DataSource bean.
Database.Host=localhost
database.User=admin
Question 7. What Is The Difference Between An Embedded Container And A War?
Answer :
There is not any force to head box much less
Embedded container is just one feature of Spring Boot
Traditional WAR also advantages a lot from Spring Boot
Automatic Spring MVC setup, such as DispatcherServlet
Sensible defaults based totally on the classpath content material
Embedded field may be used during development.
J2EE Tutorial Core Java Interview Questions
Question eight. What Embedded Containers Does Spring Boot Support?
Answer :
Spring Boot includes support for embedded Tomcat, Jetty, and Undertow servers. By default the embedded server will listen for HTTP requests on port 8080.
Question nine. What Is A Spring Boot Starter Pom? Why Is It Useful?
Answer :
Starters are a fixed of handy dependency descriptors that you may encompass on your utility. The starters incorporate a variety of the dependencies that you want to get a mission up and strolling quick and with a constant, supported set of managed transitive dependencies.
The starter POMs are handy dependency descriptors that can be brought on your utility’s Maven. In easy words, in case you are growing a task that makes use of Spring Batch for batch processing, you simply should include spring-boot-starter-batch so one can import all the required dependencies for the Spring Batch application. This reduces the burden of searching and configuring all the dependencies required for a framework.
Hibernate Interview Questions
Question 10. Can You Control Logging With Spring Boot? How?
Answer :
Yes, we will manage logging with spring boot.
Customizing default Configuration for Logging:
By adding logback.Xml report to the application we will override the default logging configuration imparting by means of the Spring Boot. This file vicinity within the classpath (src/foremost/resources) of the software for Spring Boot to pick out the custom configuration.
Spring Boot can manipulate the logging stage
Just set it in utility.Properties
Works with maximum logging frameworks
Java Util Logging, Logback, Log4J, Log4J2
logging.Degree.Org.Springframework=DEBUG
logging.Degree.Com.Acme.Your.Code=INFO
Core Java Tutorial
Question eleven. How To Reload My Changes On Spring Boot Without Having To Restart Server?
Answer :
Include following maven dependency in the application.
<dependency>
<groupId>org.Springframework</groupId>
<artifactId>springloaded</artifactId>
<version>1.2.6.RELEASE</version>
</dependency>
Automatic restart
Applications that use spring-boot-devtools will routinely restart on every occasion documents on the classpath alternate. This can be a beneficial characteristic whilst running in an IDE because it gives a very rapid remarks loop for code modifications. By default, any entry on the classpath that factors to a folder might be monitored for changes.
<dependency>
<groupId>org.Springframework.Boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
<optional>true</optional>
</dependency>
This can be accomplished the usage of DEV Tools. With this dependency any modifications you save, the embedded tomcat will restart. Spring Boot has a Developer tools (DevTools) module which helps to enhance the productivity of builders. One of the key undertaking for the Java developers is to vehicle installation the report changes to server and car restart the server. Developers can reload changes on Spring Boot while not having to restart my server. This will removes the need for manually deploying the modifications whenever. Spring Boot doesn’t have this option whilst it has released it’s first model. This turned into a maximum requested capabilities for the builders. The module DevTools does precisely what is needed for the developers. This module could be disabled within the manufacturing surroundings.
MVC Framework Interview Questions
Question 12. What Is Actuator In Spring Boot?
Answer :
Spring Boot Actuator is a sub-venture of Spring Boot. It provides several manufacturing grade services for your utility with little effort in your component. There are also has many functions delivered on your application out-of-the-field for managing the carrier in a manufacturing (or other) surroundings. They’re in particular used to expose one of a kind varieties of facts about the running application – fitness, metrics, info, unload, env and so forth.
Adv Java Interview Questions
Question 13. How To Run Spring Boot Application To Custom Port ?
Answer :
In software.Properties, add following assets.
Server.Port = 8181.
Hibernate Tutorial
Question 14. How To Implement Security For Spring Boot Application ?
Answer :
Add spring security starter to the boot application
<dependency>
<groupId>org.Springframework.Boot</groupId>
<artifactId>spring-boot-starter-protection</artifactId>
</dependency>
Question 15. What Is The Configuration File Name Used By Spring Boot?
Answer :
The configuration file utilized in spring boot projects is application.Properties. This document is very essential in which we would over write all the default configurations. Normally we ought to hold this file underneath the assets folder of the project.
Framework7 Interview Questions
Question 16. How To Implement Spring Web Using Spring Boot?
Answer :
Web Application Convenience
Boot robotically configures
A DispatcherServlet & ContextLoaderListener
Spring MVC the use of equal defaults as @EnableWebMvc
Plus many useful extra capabilities:
Static sources served from classpath
/static, /public, /sources or /META-INF/resources
Templates served from /templates
If Velocity, Freemarker, Thymeleaf, or Groovy on classpath
Provides default /error mapping
Easily overridden
Default MessageSource for I18N
MVC Framework Tutorial
Question 17. How To Configure Datasource Using Spring Boot?
Answer :
Use either spring-boot-starter-jdbc or spring-boot-starterdata-jpa and encompass a JDBC driving force on classpath
Declare homes:
spring.Datasource.Url=jdbc:mysql://localhost/check
spring.Datasource.Username=dbuser
spring.Datasource.Password=dbpass
spring.Datasource.Driver-elegance-name=com.Mysql.Jdbc.Driver
Spring Boot will create a DataSource with houses set
Will even use a connection pool if the library is determined on the classpath.
Maven Interview Questions
Question 18. What Is Yaml?
Answer :
Yaml Ain’t a Markup Language
Recursive acronym
Created in 2001
Alternative to .Properties files
Allows hierarchical configuration
Java parser for YAML is called SnakeYAML
Must be within the classpath
Provided by means of spring-boot-starters.
J2EE Interview Questions
Question 19. Why Did You Use Spring Boot In Your Application?
Answer :
As discussed in advance, Spring boot makes it simpler a good way to create Spring utility, it could store a variety of time and efforts.
For instance: Let’s say you want to create Spring boot assignment with activeMQ. You can sincerely use “spring–boot–starter–activemq” as artifact Id, it'll take all of the defaults and create Spring software with ActiveMQ configured. Let’s say you don’t want to use in-built activeMQ, you can truly override “spring.Activemq.Broking-url” in utility.Homes to apply external ActiveMQ.
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Question 20. How Can You Override Default Properties In Spring Boot Project?
Answer :
Spring boot affords numerous homes which can be overridden via specifying them in utility.Residences.
For example: You need to specify prefix and suffix in Spring MVC applications. You can virtually do it by placing underneath properties in application.Residences.
Spring.Mvc.View.Prefix: /WEB-INF/
spring.Mvc.View.Suffix: .Jsp
JUnit Interview Questions
Question 21. How Can You Run Spring Boot Application On Custom Port?
Answer :
You can actually put server.Port properties in utility.Homes.
For example:server.Port=8050.
Question 22. What Is Spring Boot Starter And How It Is Useful?
Answer :
Spring boot comes with quite a few starters which is ready of convenient dependency descriptors which you can include on your pom.Xml.
For instance: Let’s say you want to work Spring MVC application, you could in reality include “spring–boot–starter–net” as dependency in pom.Xml .
Maven Tutorial
Question 23. Can We Use Spring Boot With Applications Which Are Not Using Spring?
Answer :
No, it isn't possible as of now. Spring boot is confined to Spring programs best.
Log4j Interview Questions
Question 24. What Is Name Of The Configuration File Which You Use In Spring Boot?
Answer :
Configuration file used in Spring boot projects is software.Homes. It may be very essential record as it's far used to override all default configurations.
Core Java Interview Questions
Question 25. What Is Devtools In Spring Boot?
Answer :
Spring boot comes with DevTools that is introduced to boom the productivity of developer. You don’t need to set up your utility every time you are making the changes.Developer can definitely reload the modifications with out restart of the server. It avoids ache of deploying software on every occasion whilst you make any exchange. This module can be disabled in production surroundings.
JUnit Tutorial
Question 26. How Can You Implement Spring Security In Spring Boot Application?
Answer :
Implementation of Spring protection in Spring boot utility requires little or no configuration. You need to add spring-boot-starter-protection starter in pom.Xml.You need to create Spring config elegance if you want to amplify WebSecurityConfigurerAdapter and override required approach to reap security in Spring boot software.
Spring MVC Framework Interview Questions
Question 27. What Are Embedded Containers Which Are Supported By Spring Boot?
Answer :
Spring boot contains embedded Tomcat, Jetty and undertow servers.
Hibernate Interview Questions
Question 28. Have You Used Activemq In Spring Boot Application? Do You Know How To Configure External Activemq?
Answer :
Spring Boot comes with embedded ActiveMQ.We need to apply “spring–boot–starter–activemq” dependency in pom.Xml and it'll contend with all defaults and could configure ActiveMQ in the venture.
If you need to configure external ActiveMQ then you definately need to just put “spring.Activemq.Broking-url” in software.Properties and offer the URL of outside ActiveMQ.
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