Learn SPRING-BOOT with Real Code Examples

Spring Boot allows developers to create stand-alone, production-ready Spring applications quickly.

It provides embedded servers like Tomcat, Jetty, or Undertow, removing deployment complexity.

Supports auto-configuration to reduce boilerplate code.

Integrates seamlessly with Spring ecosystem: Spring Data, Spring Security, Spring MVC, etc.

Widely used for microservices, REST APIs, and enterprise-grade backend systems.

Dependency injection and inversion-of-control via Spring Core

Auto-configuration based on classpath and beans

Embedded server (Tomcat, Jetty, Undertow)

Spring MVC for web and REST endpoints

Spring Data integration for ORM and database access

Spring Boot application instance - entry point class

Controllers - define REST endpoints

Services - business logic layer

Repositories - data access layer with Spring Data

Beans - managed objects via dependency injection

src/main/java/ - main application code

src/main/resources/ - configuration files, static assets, templates

controllers/ - REST controllers

services/ - business logic classes

repositories/ - database access interfaces

Create Spring Boot project using Spring Initializr

Define REST controllers with `@RestController`

Implement business logic in service classes

Configure data access with Spring Data repositories

Run application using embedded server

Beginner: simple REST endpoints

Intermediate: CRUD API with database integration

Advanced: authentication and authorization

Expert: microservices with service discovery

Auditor: monitor performance and optimize metrics

Spring Boot vs Spring MVC: Boot adds auto-configuration and embedded server

Spring Boot vs Flask: Java enterprise ecosystem vs Python lightweight

Spring Boot vs FastAPI: Spring Boot is Java, FastAPI is Python with async support

Spring Boot vs Express.js: Full-featured vs minimal Node.js framework

Spring Boot vs Micronaut: Boot is mature, Micronaut optimized for startup and memory

2014 – Spring Boot initial release

2015 – Spring Boot 1.2 with Actuator and DevTools

2016–2018 – Spring Boot 2.x with reactive support

2019–2021 – Cloud-native and Kubernetes integration

2022–2025 – Enhanced performance, security, and observability

Spring Boot application - entry point class with `@SpringBootApplication`

Controller - REST endpoints handler

Service - business logic class

Repository - interface for database access

Bean - managed object in Spring context