Top 100 Spring Boot Interview Questions and Answers

Spring is a framework while Spring Boot is an extension of Spring.

• Spring Boot provides auto-configuration and embedded servers.

• Spring Boot reduces boilerplate code and simplifies application setup.

• Spring Boot is opinionated and provides defaults for configuration.

• Spring Boot is ideal for microservices and standalone applications.

• Spring is more flexible and customizable than Spring Boot.

Spring Boot is a framework for building standalone, production-grade Spring-based applications.

• Simplifies the process of creating and deploying Spring-based applications

• Provides a range of pre-configured features and dependencies

• Enables rapid development and prototyping

• Supports a variety of deployment options, including cloud-based platforms

• Offers a range of plugins and tools for development and testing

• Improves developer productivity and reduces time-to-market

Spring is a framework for building Java applications, while Spring Boot is a tool for quickly creating Spring-based applications.

• Spring provides a comprehensive framework for building Java applications, while Spring Boot is a tool that simplifies and accelerates the process of creating Spring-based applications.

• Spring requires more configuration and setup, while Spring Boot provides a pre-configured environment that requires minimal setup.

• Spring Boot includes an embedded web ...read more

A convenience annotation that combines @Configuration, @EnableAutoConfiguration, and @ComponentScan.

• Used to bootstrap a Spring Boot application.

• Automatically configures the Spring application based on the dependencies added to the classpath.

• Scans the package and its sub-packages for components and services.

• Example: @SpringBootApplication public class MyApplication { public static void main(String[] args) { SpringApplication.run(MyApplication.class, args); } }

SpringBootApplication is a combination of three annotations in Spring Boot.

• SpringBootApplication is a meta-annotation that combines @Configuration, @EnableAutoConfiguration, and @ComponentScan annotations.

• @Configuration annotation indicates that the class is a source of bean definitions.

• @EnableAutoConfiguration annotation enables Spring Boot to automatically configure the application based on the dependencies added to the classpath.

• @ComponentScan annotation tells Spring to sc...read more

To connect 2 DBs from a Spring Boot application, configure multiple data sources and use JdbcTemplate or EntityManager for each DB.

• Configure multiple data sources in the application.properties file

• Create separate configuration classes for each data source

• Use JdbcTemplate or EntityManager to interact with each DB

• Specify the appropriate data source in the repository or service classes

Annotation used in Spring Boot to enable the application to be run from a main method.

• Used to mark a class as the main entry point for a Spring Boot application

• Eliminates the need for a traditional main method

• Can be used in combination with @SpringBootApplication annotation

Spring Boot is a framework for building Java-based applications with minimal configuration. Microservices is an architectural style where applications are composed of small, independent services.

• Spring Boot is used to simplify the development of Java applications by providing pre-configured settings and dependencies.

• Microservices architecture breaks down applications into smaller, loosely coupled services that can be developed, deployed, and scaled independently.

• Spring Boot c...read more

Create a Spring Boot application with GET and POST methods

• Create a new Spring Boot project using Spring Initializr

• Define a controller class with methods for GET and POST requests

• Use @GetMapping and @PostMapping annotations to map requests to methods

• Implement the logic for handling GET and POST requests in the controller class

• Run the Spring Boot application and test the GET and POST endpoints

Spring Boot dependency injection is a design pattern where objects are passed their dependencies rather than creating them internally.

• In Spring Boot, dependency injection is achieved through the use of @Autowired annotation.

• It helps in achieving loose coupling between classes and promotes easier testing and maintenance.

• Example: @Autowired private UserService userService; // Injecting UserService dependency

A Spring Boot REST controller is used to handle incoming HTTP requests and return appropriate responses.

• Create a new Java class annotated with @RestController

• Define request mapping annotations like @GetMapping, @PostMapping, @PutMapping, @DeleteMapping

• Inject dependencies using @Autowired annotation

• Return response using ResponseEntity or directly as method return value

Spring Boot is a framework that simplifies the development of Java applications by providing pre-configured templates and components.

• Spring Boot provides a set of pre-configured templates and components that can be used to quickly develop Java applications.

• It includes features like auto-configuration, embedded servers, and production-ready metrics.

• Spring Boot also integrates with other Spring frameworks like Spring Data and Spring Security.

• Some of the key components of Spring...read more

Spring Boot validation is a feature that allows developers to validate input data in a Spring Boot application.

• Spring Boot validation is used to ensure that the data entered by the user meets certain criteria.

• It can be applied to request parameters, request bodies, and path variables.

• Annotations like @NotNull, @Size, @Email, etc., are commonly used for validation.

• Custom validation logic can also be implemented using custom annotations and validators.

Spring Boot provides rapid development, easy configuration, and production-ready applications.

• Rapid development with auto-configuration and starter dependencies

• Embedded HTTP server for easy deployment

• Production-ready features like metrics, health checks, and externalized configuration

• Support for building microservices and cloud-native applications

• Integration with popular frameworks like Spring Cloud, Hibernate, and Apache Kafka

Performance issues in Spring Boot can be handled by optimizing code, using caching, monitoring application metrics, and tuning database queries.

• Optimize code by reducing unnecessary loops, improving algorithms, and minimizing database calls.

• Use caching mechanisms like Spring Cache to store frequently accessed data in memory.

• Monitor application metrics using tools like Spring Boot Actuator to identify bottlenecks and optimize performance.

• Tune database queries by indexing colum...read more

Spring is a framework for building Java applications, while Spring Boot is a tool for quickly creating standalone Spring-based applications.

• Spring is a comprehensive framework for building Java applications, providing support for dependency injection, aspect-oriented programming, and more.

• Spring Boot is an opinionated tool that simplifies the setup and configuration of Spring applications, allowing for quick development of standalone applications.

• Spring Boot includes embedded...read more

Creating API's using Spring Boot framework for Java development

• Use @RestController annotation to define RESTful web services

• Define request mappings using @RequestMapping annotation

• Use @GetMapping, @PostMapping, @PutMapping, @DeleteMapping annotations for specific HTTP methods

• Use @RequestBody annotation to bind incoming HTTP request body to a Java object

• Use ResponseEntity to return custom HTTP status codes and headers

Develop a Spring Boot API for a given table

• Create a Spring Boot project with necessary dependencies

• Define entity class representing the table

• Create a repository interface extending JpaRepository

• Implement service layer with business logic

• Create REST controller with CRUD operations

Spring Boot is a framework that simplifies the development of Java applications by providing pre-configured settings and tools.

• Spring Boot eliminates the need for manual configuration by providing defaults for most settings.

• It allows for easy creation of standalone, production-grade Spring-based Applications.

• Spring Boot uses embedded servers like Tomcat, Jetty, or Undertow to simplify deployment.

• It provides a wide range of plugins to support various functionalities like secur...read more

Enable debugging log in Spring Boot application

• Add 'logging.level.root=DEBUG' in application.properties file

• Use '@Slf4j' annotation in the Java class to enable logging

• Set 'logging.level.org.springframework=DEBUG' for Spring framework debugging

Authentication in Spring Boot is handled using Spring Security which provides various authentication mechanisms.

• Use Spring Security to configure authentication in Spring Boot

• Define a custom UserDetailsService to load user-specific data for authentication

• Use annotations like @EnableWebSecurity and @EnableGlobalMethodSecurity to secure endpoints

• Configure authentication providers like in-memory, JDBC, LDAP, etc. in the application.properties file

Load balancing in Spring Boot can be achieved using various techniques such as server-side load balancing, client-side load balancing, and using a load balancer.

• Server-side load balancing can be achieved by using technologies like Ribbon or Eureka in Spring Cloud.

• Client-side load balancing can be implemented by using technologies like Feign or RestTemplate in Spring Cloud.

• Using a load balancer like Nginx or Apache in front of Spring Boot application can also help in achieving...read more

Use Spring Data JPA to connect Spring Boot project with database.

• Add database configuration in application.properties or application.yml file

• Create entity classes annotated with @Entity and @Table

• Create repository interfaces extending JpaRepository

• Use @Autowired annotation to inject repository in services or controllers

Spring Boot applications can be deployed using various methods such as embedded servers, Docker containers, and cloud platforms.

• Deploying as a standalone JAR file using embedded servers like Tomcat or Jetty

• Building a Docker image and running the application in a container

• Deploying to cloud platforms like AWS, Azure, or Google Cloud Platform

• Using CI/CD pipelines for automated deployment

Yes, I have done customisation in spring-boot.

• Implemented custom error handling by extending ResponseEntityExceptionHandler

• Created custom annotations for validation

• Configured custom logging using Logback

Implement CRUD operations for user table in a Spring Boot project.

• Create a Spring Boot project using Spring Initializr

• Define a User entity with necessary fields and annotations

• Create a UserRepository interface extending JpaRepository

• Implement methods in a UserService class for CRUD operations

• Use RESTful endpoints to expose the CRUD operations

Integrating Spring Data JPA with Spring Boot allows for easy database operations in a Spring Boot application.

• Add Spring Data JPA dependency in pom.xml

• Create JPA entity classes annotated with @Entity

• Create a repository interface extending JpaRepository

• Use repository interface in service classes for database operations

• Configure application.properties with database connection details

Creating API using Spring Boot for software development.

• Use @RestController annotation to define RESTful web services.

• Define request mappings using @RequestMapping annotation.

• Use @GetMapping, @PostMapping, @PutMapping, @DeleteMapping annotations for specific HTTP methods.

• Use @RequestBody annotation to bind HTTP request body to a method parameter.

• Use @ResponseBody annotation to bind the return value to the HTTP response body.

Actuator is a Spring Boot module that provides endpoints for monitoring and managing the application.

• Actuator exposes various endpoints for monitoring and managing the application

• It provides health, metrics, info, and other endpoints

• These endpoints can be accessed via HTTP or JMX

• Actuator can be configured to secure the endpoints with authentication and authorization

• Actuator can also be extended to provide custom endpoints

To communicate two APIs in Spring Boot, you can use RestTemplate or WebClient to make HTTP requests.

• Use RestTemplate to make synchronous HTTP requests between APIs

• Use WebClient to make asynchronous HTTP requests between APIs

• Implement error handling and exception handling for robust communication

• Consider using Feign client for declarative REST client

• Ensure proper authentication and authorization mechanisms are in place

Deploying a Spring Boot application on AWS involves creating a deployment package and using AWS services like Elastic Beanstalk or EC2.

• Create a deployment package of the Spring Boot application (e.g. JAR file)

• Choose an AWS service like Elastic Beanstalk or EC2 for deployment

• Configure the AWS service with necessary settings like environment variables, instance type, etc.

• Upload the deployment package to AWS and start the application

Spring Boot annotations are used to simplify the development process by providing shortcuts for common tasks.

• Annotations like @SpringBootApplication, @RestController, @Autowired, @GetMapping, @PostMapping are commonly used in Spring Boot applications.

• These annotations help in configuring the application, defining REST endpoints, injecting dependencies, and mapping HTTP requests to controller methods.

• For example, @SpringBootApplication is used to mark the main class of a Sprin...read more

Use Spring Boot configuration to connect master and slave instances of a DB

• Configure multiple data sources in application.properties or application.yml file

• Use @Primary annotation for the master data source and @Qualifier annotation for the slave data source

• Define separate DataSource, JdbcTemplate, and EntityManager beans for each data source

• Use @Transactional annotation with the appropriate data source to specify which database to use for transactions

To print something on browser using Spring Boot, you can create a controller method that returns a view or a response entity.

• Create a controller class with a method that returns a view or a response entity

• Use Thymeleaf or other template engine to render HTML views

• Return a response entity with the content type set to text/html for plain text output

Create a Spring Boot application to generate an XML file from two input values.

• Create a Spring Boot project using Spring Initializr

• Create a REST controller to accept two input values

• Use JAXB to generate XML from the input values

• Return the generated XML file as response

AWS SDK for Java provides APIs to connect with AWS services from Spring Boot application.

• Add AWS SDK for Java dependency in Spring Boot project

• Create an instance of AWS service client using AWS SDK for Java

• Use the client to interact with AWS services

• Configure AWS credentials and region in application.properties file

• Example: Connect to S3 bucket using AWS SDK for Java in Spring Boot

Spring Boot starters are dependency descriptors that simplify the dependency management process in Spring Boot applications.

• Spring Boot starters provide a set of pre-configured dependencies that can be easily included in your project.

• They help in reducing the amount of boilerplate code needed to set up a Spring Boot application.

• Starters are typically named with the format 'spring-boot-starter-*', where * represents the specific functionality or technology being included.

• For e...read more

Multithreading in Spring Boot allows for concurrent execution of tasks, improving performance and responsiveness.

• Spring Boot provides support for multithreading through the use of @Async annotation.

• By annotating a method with @Async, it will be executed in a separate thread.

• ThreadPoolTaskExecutor can be configured to control the number of threads used for executing async methods.

• Example: @Async public void asyncMethod() { // method logic }

Transactions in Spring Boot help manage database operations as a single unit of work.

• Transactions ensure that all database operations either succeed or fail together.

• Use @Transactional annotation to mark a method as transactional.

• Transactions can be managed programmatically using TransactionTemplate.

• Spring Boot supports declarative transaction management using @EnableTransactionManagement.

• Example: @Transactional public void saveData() { // save data to database }

Low level design involves creating detailed technical specifications for building a Spring Boot app.

• Identify the components and their interactions in the app

• Define the data model and database schema

• Design the RESTful APIs and their endpoints

• Implement security measures such as authentication and authorization

• Optimize performance by considering caching and asynchronous processing

Tomcat and Spring Boot versions are independent of each other, but they can be compatible with each other.

• Tomcat versions can range from 7.x to 10.x, with the latest stable version being 10.0.12.

• Spring Boot versions are typically aligned with Spring Framework versions, with the latest stable version being 2.5.4.

• It is important to ensure compatibility between the Tomcat and Spring Boot versions being used in a project.

Spring is a framework while Spring Boot is an extension of Spring. Spring Boot uses annotations to simplify configuration.

• Spring is a framework for building Java applications

• Spring Boot is an extension of Spring that simplifies configuration

• Spring Boot uses annotations to configure the application

• Spring Boot provides a lot of defaults and auto-configuration

• Spring Boot is ideal for microservices and cloud-native applications

To configure 2 databases in one Spring Boot app, define multiple DataSource beans and specify which entity manager to use for each database.

• Define multiple DataSource beans in the configuration class

• Specify which entity manager to use for each database

• Use @Primary annotation for the default database

Spring Boot is used for developing stand-alone, production-grade Spring-based applications.

• Spring Boot simplifies the development process by providing auto-configuration and opinionated defaults.

• It allows developers to quickly create and deploy applications with minimal configuration.

• Spring Boot provides a range of features like embedded servers, metrics, health checks, and security.

• It supports various technologies and frameworks, making it easy to integrate with existing sys...read more

Spring is a framework for building Java applications, while Spring Boot is a tool that simplifies the setup and configuration of Spring applications.

• Spring is a comprehensive framework that provides support for various functionalities like dependency injection, aspect-oriented programming, and more.

• Spring Boot is an opinionated tool that simplifies the setup and configuration of Spring applications by providing defaults and auto-configuration.

• Spring Boot includes embedded ser...read more

A spring starter is a mechanical device used to start an engine by storing energy in a spring and releasing it to turn the engine's crankshaft.

• Spring starters are commonly used in small engines, such as those found in lawnmowers or chainsaws.

• The spring is wound up manually or by pulling a cord, and when released, it rapidly unwinds to start the engine.

• Spring starters are often used as a backup to electric starters in case of battery failure.

• Examples of engines that may use sp...read more

Spring is a framework while Spring Boot is an extension of Spring.

• Spring Boot provides a pre-configured environment for Spring applications.

• Spring Boot reduces the amount of boilerplate code required for setting up a Spring application.

• Spring Boot includes an embedded server, making it easier to deploy applications.

• Spring Boot provides a range of starter dependencies for common use cases.

• Spring Boot is ideal for microservices architecture.

• Spring is more flexible and customiza...read more

@SpringBootApplication is a Spring Boot annotation that enables auto-configuration and component scanning.

• Enables auto-configuration of the Spring application context

• Enables component scanning for beans

• Provides a convenient shortcut for @Configuration, @EnableAutoConfiguration, and @ComponentScan annotations

• Can be used as a single entry point for the Spring Boot application

To connect 2 different databases from a Spring Boot application, you can use Spring Data JPA and configure multiple data sources.

• Configure the data sources in the application.properties file

• Create separate JPA repositories for each data source

• Use @Qualifier annotation to specify which data source to use in each repository

• Inject the repositories in your service classes

• Use @Transactional annotation to ensure atomicity across both data sources

Spring Boot is a Java-based framework used for creating standalone, production-grade Spring-based Applications.

• Spring Boot simplifies the process of creating Spring applications by providing a set of default configurations.

• It allows developers to quickly set up and run standalone Spring applications.

• Spring Boot includes embedded servers like Tomcat, Jetty, or Undertow, making it easy to deploy applications.

• It provides production-ready features such as metrics, health checks, ...read more

Spring Boot simplifies the development of Java applications by providing a set of tools and conventions for building production-ready applications quickly.

• Provides a pre-configured environment for developing and deploying Java applications

• Reduces the need for boilerplate code and configuration

• Supports embedded servers for easy deployment

• Offers built-in support for monitoring, metrics, and health checks

• Integrates seamlessly with other Spring projects like Spring Data, Spring S...read more

To connect a database to a Spring Boot application, you need to configure the database properties and dependencies in the application's configuration files.

• Add the necessary database dependencies in the project's build file (e.g., pom.xml for Maven).

• Configure the database connection properties in the application.properties or application.yml file.

• Create a DataSource bean to establish the connection with the database.

• Use JPA (Java Persistence API) or JDBC (Java Database Connec...read more

Spring Boot microservices are small, independent, loosely coupled services built using the Spring Boot framework.

• Microservices are small, independent services that work together to form a larger application.

• Spring Boot is a framework that simplifies the development of Java-based applications.

• Spring Boot microservices are designed to be easily deployable and scalable.

• Each microservice typically handles a specific business function or domain.

• Communication between microservices ...read more

Create a REST service using Spring Boot

• Create a new Spring Boot project

• Add dependencies for Spring Web and Spring Boot DevTools in pom.xml

• Create a new Java class for the REST controller with @RestController annotation

• Define request mapping annotations like @GetMapping, @PostMapping, @PutMapping, @DeleteMapping for different HTTP methods

• Implement the business logic for each endpoint

• Run the Spring Boot application and test the REST service using tools like Postman

Dependency Injection is a design pattern in Spring Boot where the dependencies of a class are injected from the outside.

• In Spring Boot, Dependency Injection is achieved through inversion of control, where the control of creating and managing objects is given to the Spring framework.

• Dependencies can be injected into a class using constructor injection, setter injection, or field injection.

• By using Dependency Injection, classes become more loosely coupled, making them easier to...read more

Spring MVC is a web framework for building web applications using the Model-View-Controller design pattern. Spring Boot is a tool for quickly creating stand-alone, production-grade Spring-based applications.

• Spring MVC is a part of the Spring Framework that provides a model-view-controller architecture for building web applications.

• It helps in separating the different aspects of a web application like business logic, user interface, and input logic.

• Spring Boot is a tool that s...read more

Spring Boot is a framework that uses various components to simplify the development of Java applications.

• Spring Core: Provides dependency injection and inversion of control.

• Spring MVC: Enables building web applications.

• Spring Data: Simplifies database access and integration.

• Spring Security: Handles authentication and authorization.

• Spring Boot Actuator: Provides production-ready features for monitoring and managing applications.

• Spring Boot Starter: Pre-configured dependencies ...read more

Some important Spring Boot annotations include @SpringBootApplication, @RestController, @Autowired, @RequestMapping, @ComponentScan.

• @SpringBootApplication - Used to mark the main class of a Spring Boot application.

• @RestController - Used to define RESTful web services.

• @Autowired - Used for automatic dependency injection.

• @RequestMapping - Used to map web requests to specific handler methods.

• @ComponentScan - Used to specify the base packages to scan for Spring components.

Spring Boot simplifies the setup and development of Spring applications by providing a convention-over-configuration approach.

• Spring Boot eliminates the need for XML configuration by using annotations and sensible defaults.

• It includes embedded servers like Tomcat, Jetty, or Undertow, making it easy to deploy standalone applications.

• Auto-configuration feature reduces the amount of boilerplate code needed to set up a Spring application.

• Actuator module provides production-ready ...read more

Spring is a framework for building Java applications, while Spring Boot is a tool for easily creating stand-alone, production-grade Spring-based applications.

• Spring is a framework that provides comprehensive infrastructure support for developing Java applications.

• Spring Boot is a tool that simplifies the process of creating stand-alone, production-grade Spring-based applications.

• Spring Boot eliminates the need for a lot of configuration, allowing developers to quickly set up ...read more

Spring is a Java framework for building enterprise applications. Spring Boot is a tool that simplifies the setup and development of Spring applications.

• Spring is a powerful Java framework used for building enterprise applications.

• It provides comprehensive infrastructure support for developing Java applications.

• Spring Boot is an extension of the Spring framework that simplifies the setup and development of Spring applications.

• It allows for rapid application development by prov...read more

Spring is a framework for building Java applications, while Spring Boot is an extension that simplifies the setup and development process.

• Spring is a comprehensive framework that provides infrastructure support for developing Java applications.

• Spring Boot is an extension of the Spring framework that simplifies the setup and development of Spring applications.

• Spring Boot includes features like auto-configuration, embedded servers, and production-ready metrics.

• Spring Boot allow...read more

Use Spring Boot's multiple datasource configuration to work with 2 different databases

• Define multiple datasource configurations in application.properties or application.yml

• Create separate DataSource and JdbcTemplate beans for each database

• Use @Primary annotation to specify the primary datasource

• Use @Qualifier annotation to specify the secondary datasource

• Inject the appropriate datasource in your repository classes

Spring Boot is a framework that simplifies the development of Java applications by providing pre-configured settings and tools.

• Spring Boot eliminates the need for manual configuration by providing defaults for most settings.

• It allows developers to create stand-alone, production-grade Spring-based Applications that can be up and running with minimal setup.

• Spring Boot includes an embedded server, such as Tomcat, making it easy to deploy applications.

• It offers a wide range of pl...read more

Spring Boot simplifies the development of Java applications by providing a set of tools and conventions for building production-ready applications quickly.

• Provides a pre-configured environment for building standalone, production-grade Spring-based applications

• Reduces the need for boilerplate code and configuration, allowing developers to focus on business logic

• Supports embedded servers like Tomcat, Jetty, and Undertow for easy deployment

• Offers a wide range of plugins and exte...read more

Spring Boot allows multiple database connections through configuration and using multiple data sources.

• Configure multiple data sources in application.properties or YAML file

• Create separate DataSource and JdbcTemplate beans for each data source

• Use @Qualifier annotation to specify which data source to use in a repository or service

• Example: https://www.baeldung.com/spring-data-jpa-multiple-databases

Microservices in Spring Boot allow for building modular, scalable applications.

• Spring Boot provides a lightweight framework for building microservices

• Each microservice can be developed and deployed independently

• Communication between microservices can be achieved through REST APIs or messaging queues

• Spring Cloud provides additional tools for managing microservices architecture

Spring MVC is a web framework while Spring Boot is an opinionated way of building Spring applications.

• Spring MVC requires more configuration and setup compared to Spring Boot

• Spring Boot provides a pre-configured environment for building Spring applications

• Spring Boot includes an embedded server, making it easier to deploy applications

• Spring MVC is more flexible and customizable compared to Spring Boot

• Both frameworks are built on top of the Spring framework

Springboot is a framework that simplifies the development of Java applications, while Spring is a more comprehensive framework for building enterprise applications.

• Springboot is opinionated and provides defaults for configuration, making it easier to get started quickly.

• Springboot is ideal for microservices and standalone applications, while Spring is better suited for larger, complex applications.

• Springboot includes embedded servers like Tomcat or Jetty, while Spring require...read more

Spring Boot is a framework that simplifies the development of Spring applications by providing pre-configured settings and conventions.

• Spring Boot eliminates the need for manual configuration by providing default settings and auto-configuration.

• It reduces the development time and effort required to set up a Spring application.

• Spring Boot includes embedded servers like Tomcat, Jetty, and Undertow, making it easier to deploy standalone Spring applications.

• It offers a variety of...read more

Spring Boot is a framework used to simplify the development of Java applications by providing pre-configured settings and tools.

• Spring Boot helps in creating stand-alone, production-grade Spring-based applications.

• It eliminates the need for manual configuration by providing default settings.

• It offers a range of features like embedded servers, metrics, health checks, and more.

• Spring Boot is commonly used for building microservices and web applications.

• It allows for easy integr...read more

Spring Boot simplifies the setup and development of Spring applications by providing default configurations and reducing boilerplate code.

• Spring Boot provides a set of default configurations which reduces the need for manual setup and configuration.

• It eliminates the need for XML configurations and reduces boilerplate code, making development faster and more efficient.

• Spring Boot includes embedded servers like Tomcat, Jetty, or Undertow, making it easy to deploy standalone Spr...read more

Database connection in Spring Boot is configured using application.properties or application.yml file.

• Define database connection properties in application.properties or application.yml file

• Use @EnableJpaRepositories annotation to enable JPA repositories

• Use @Entity annotation to define entity classes

• Use @Autowired annotation to inject the DataSource or EntityManager

Bean annotation is used in Spring Boot on class or method to indicate that a method produces a bean to be managed by the Spring container.

• Bean annotation is used on methods within a class to indicate that the method produces a bean to be managed by the Spring container.

• It can also be used at the class level to indicate that the class itself is a Spring bean.

• For example, @Bean annotation can be used on a method that creates and returns a DataSource bean in a configuration clas...read more

Circular dependency in Spring Boot occurs when two or more beans depend on each other directly or indirectly.

• Circular dependency can lead to runtime errors or application startup failures.

• To resolve circular dependencies, you can use constructor injection, setter injection, or @Lazy annotation.

• Example: Bean A depends on Bean B, and Bean B depends on Bean A.

Spring MVC is a framework for building web applications using the Model-View-Controller design pattern, while Spring Boot is an opinionated framework for quickly building production-ready applications.

• Spring MVC is more customizable and requires more configuration compared to Spring Boot.

• Spring Boot provides a set of defaults and auto-configuration options to simplify development.

• Spring Boot is ideal for microservices and standalone applications, while Spring MVC is better su...read more

Spring Boot is an opinionated framework that simplifies Spring development.

• Spring Boot provides auto-configuration and embedded servers.

• Spring Boot reduces boilerplate code and configuration.

• Spring Boot is ideal for microservices and standalone applications.

• Spring provides a more flexible and customizable framework.

• Spring requires more configuration and setup.

• Spring is ideal for large-scale enterprise applications.

Spring Boot is a framework that simplifies the development of Java applications by providing pre-configured settings and tools.

• Spring Boot follows a convention over configuration approach, reducing the need for manual configuration.

• It includes embedded servers like Tomcat, Jetty, or Undertow, making it easy to deploy standalone applications.

• Spring Boot uses annotations to simplify the configuration of beans, controllers, and other components.

• It provides a wide range of starte...read more

Major changes in Spring Boot 3 include support for Java 17, improved performance, and enhanced security features.

• Support for Java 17

• Improved performance optimizations

• Enhanced security features such as OAuth 2.1 support

• Updated dependencies and libraries

The task involves using Spring Boot and a database.

• Use Spring Boot framework to develop the application

• Connect to a database using Spring Data JPA

• Implement CRUD operations for database entities

• Use annotations like @RestController, @RequestMapping, @Autowired, etc.

• Handle exceptions and validations in the application

• Write unit tests for the application

Spring Boot is a framework that simplifies the development of Java applications by providing pre-configured settings and dependencies.

• Spring Boot is built on top of the Spring framework and follows the convention over configuration principle.

• It provides a standalone executable JAR file that includes an embedded server, making it easy to deploy and run applications.

• Spring Boot offers auto-configuration, which automatically configures the application based on the dependencies p...read more

A Spring Boot application follows a predefined flow of execution.

• Application starts with main() method

• Spring Application Context is initialized

• Beans are created and dependencies are injected

• Application starts serving requests

• Requests are handled by Controllers and Services

• Responses are returned to the client

Spring Boot is an opinionated framework for building stand-alone, production-grade Spring-based applications. Spring MVC is a part of the Spring Framework for building web applications.

• Spring Boot is used for creating standalone Spring applications with minimal configuration, while Spring MVC is used for building web applications.

• Spring Boot provides auto-configuration and embedded servers for easy deployment, while Spring MVC requires more manual configuration.

• Spring Boot si...read more

Spring is a framework for building Java applications, while Spring Boot is an extension that simplifies the setup and development process.

• Spring is a comprehensive framework that provides various modules for different functionalities like Spring MVC, Spring Security, etc.

• Spring Boot is an opinionated framework that simplifies the setup and development process by providing defaults for configuration.

• Spring Boot includes embedded servers like Tomcat, Jetty, or Undertow, making ...read more

DI and IoC are design patterns used in Spring Boot to achieve loose coupling and improve testability.

• DI (Dependency Injection) is a design pattern where the dependencies of a class are injected from the outside rather than created within the class itself.

• IoC (Inversion of Control) is a design principle where the control of object creation and lifecycle is inverted from the class to an external entity.

• Spring Boot uses DI and IoC to manage dependencies and improve modularity an...read more

Spring Boot is a framework for building standalone, production-grade Spring-based applications.

• Spring Boot simplifies the process of creating and deploying Spring-based applications.

• It provides a range of features such as auto-configuration, embedded servers, and production-ready metrics.

• Spring Boot is highly customizable and can be used with a variety of other Spring projects and libraries.

System design of application using Spring Boot

• Identify the requirements and constraints of the system

• Choose appropriate architecture pattern (e.g. MVC, Microservices)

• Design the data model and database schema

• Implement the business logic using Spring Boot

• Configure the application properties and dependencies

• Test and deploy the application

Spring is a framework that provides comprehensive infrastructure support, while Spring Boot is a tool that simplifies Spring application development.

• Spring is a comprehensive framework that provides various modules for different functionalities like Spring MVC, Spring Security, Spring Data, etc.

• Spring Boot is a tool that simplifies the setup and configuration of Spring applications by providing defaults and auto-configuration.

• Spring Boot reduces the need for manual configurat...read more

Spring Boot is a framework that simplifies the development of Java applications by providing pre-configured settings and tools.

• Spring Boot eliminates the need for manual configuration by providing defaults for most settings.

• It allows developers to create stand-alone, production-grade Spring-based Applications.

• Spring Boot includes embedded servers like Tomcat, Jetty, or Undertow, making it easy to deploy applications.

• It offers a wide range of plugins and extensions for various...read more

Annotations in Spring Boot are used to simplify the configuration and development of Spring applications.

• Annotations are used to define the behavior of Spring components, such as controllers, services, and repositories.

• Annotations like @RestController, @Service, and @Repository are commonly used in Spring Boot applications.

• Annotations can also be used for mapping requests to controller methods, handling exceptions, and defining transaction boundaries.

• Annotations like @Autowir...read more

One disadvantage of Spring Boot is its potential for increased memory consumption.

• Spring Boot can consume more memory compared to traditional Java EE applications due to its auto-configuration and embedded server features.

• This can lead to higher resource usage and potentially slower performance.

• Developers need to be mindful of optimizing memory usage and monitoring application performance.

• Using Spring Boot for small, simple applications may result in unnecessary overhead.

Spring is a framework for building Java applications, while Spring Boot is a tool for quickly creating stand-alone Spring-based applications.

• Spring is a comprehensive framework for building Java applications, providing support for various modules like Spring MVC, Spring Data, and Spring Security.

• Spring Boot is an opinionated tool that simplifies the setup and configuration of Spring applications, allowing developers to quickly create stand-alone, production-ready applications...read more

Spring and Spring Boot are popular Java frameworks used for building enterprise applications.

• Spring is a comprehensive framework that provides support for various functionalities like dependency injection, aspect-oriented programming, and transaction management.

• Spring Boot is an opinionated framework built on top of Spring, which simplifies the setup and configuration of Spring applications by providing defaults for common configurations.

• Spring Boot includes embedded servers ...read more

Bean scopes in Spring Boot determine the lifecycle and visibility of beans.

• Singleton scope: Default scope, only one instance per Spring container

• Prototype scope: New instance created each time bean is requested

• Request scope: Bean created once per HTTP request

• Session scope: Bean created once per HTTP session

• Application scope: Bean created once per ServletContext

Dependency Injection in Spring Boot allows for loosely coupled components by injecting dependencies at runtime.

• Dependency Injection is a design pattern where objects are passed their dependencies rather than creating them internally.

• In Spring Boot, dependencies are injected using @Autowired annotation.

• By using Dependency Injection, components can be easily swapped out and tested independently.

• Example: @Autowired private UserService userService; // Injecting UserService depend...read more

Annotations like @Qualifier and @Transactional are used in Spring Boot for dependency injection and transaction management.

• Annotations like @Qualifier are used to specify which bean to inject when multiple beans of the same type are present.

• Annotations like @Transactional are used to mark a method as transactional, allowing for rollback in case of exceptions.

• Annotations like @Component, @Service, @Repository are used for component scanning and auto-wiring.

• Annotations like @Re...read more

Spring Boot is a framework that simplifies the development of Java applications by providing pre-configured settings and tools.

• Spring Boot eliminates the need for manual configuration by providing defaults for most settings.

• It allows for the creation of stand-alone, production-grade Spring-based applications.

• Spring Boot includes embedded servers like Tomcat, Jetty, or Undertow, making it easy to deploy applications.

• It offers a wide range of plugins and extensions for addition...read more