1. What is Spring Boot?

Spring Boot is a framework/project/module from "The Spring Team" (spring.io) designed to simplify the bootstrapping and development of new Spring applications. It is built on top of the existing Spring Framework to streamline the development of Spring-based applications.

• Purpose: A Rapid Application Development (RAD) tool and Spring application development accelerator.

Why Use Spring Boot?

Without Spring Boot, using only the Spring Framework involves:

1. Manual Dependency Management:
   • Programmers must manage and resolve dependencies in pom.xml.
   • Requires knowledge of exact dependencies and their compatible versions (e.g., refer to Spring MVC Hibernate’s pom.xml).
2. Comparison with Spring Boot:
   • Spring Boot provides dependency management through starter dependencies (e.g., spring-boot-starter-web, spring-boot-starter-data-jpa, spring-boot-starter-security).
   • These pre-configured dependencies simplify third-party library management and ensure compatibility within the Spring ecosystem.
   • Fewer dependencies are needed, and no version specification is required.
3. Zero Configuration:
   • Spring Boot offers automatic configuration support by analyzing:
     • Frameworks available on the CLASSPATH.
     • Existing application configuration.
   • Auto-Configuration: Provides basic configuration for frameworks based on detected dependencies.
     • Example: For ORM (e.g., Hikari DBCP vendor), selecting spring-boot-starter-web automatically configures Spring MVC components like DispatcherServlet, HandlerMapping, and ViewResolver.
4. Embedded Server:
   • No need to deploy on an external web server or create a WAR file.
   • Spring Boot includes an embedded Tomcat server, allowing applications to be packaged as standalone JAR files for deployment.
5. Production-Ready Features:
   • Spring Boot provides features like monitoring, auditing, and health checks via the spring-boot-starter-actuator dependency.
   • Enables monitoring of applications across different environments.

Key Features Summary

• Opinionated Defaults: Provides conventions and defaults to create production-ready applications with minimal configuration, reducing boilerplate and enabling focus on application logic, unit tests, and integration tests.
• Auto-Configuration: Analyzes the classpath to configure beans and components automatically, eliminating manual setup.
• Embedded Server: Includes servers like Tomcat or Jetty for standalone JAR deployment, simplifying the process.
• Production-Ready Features: Offers health checks, auditing, monitoring, logging, and external configuration for robust applications.
• Dependency Management: Simplifies library management with starter dependencies.
• Developer Productivity: Enhances productivity through convention-over-configuration, auto-configuration, and built-in tools.
• Community Support: Extensive documentation, tutorials, and active community support.
• Microservices and Cloud-Native: Well-suited for microservices and cloud-native applications, integrating with Spring Cloud for service discovery, distributed configuration, and circuit breakers.