Introduction to Spring Boot

Spring Boot is one of the most popular Java frameworks used for building modern web applications, REST APIs, and microservices. It is built on top of the Spring Framework and simplifies Java development by reducing configuration and setup time.

Developers use Spring Boot to create fast, secure, scalable, and production-ready applications with minimal code.

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Why Learn Spring Boot?

Spring Boot is widely used in the software industry because it offers:

• Easy project setup
• Embedded servers like Tomcat
• Fast application development
• REST API support
• Database integration
• Microservices architecture support
• Security features
• Cloud deployment support

Many companies such as Amazon, Netflix, and Google use Spring Boot-based systems for scalable backend services.

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Features of Spring Boot

1. Auto Configuration

Spring Boot automatically configures your project based on dependencies present in the application.

Example: If MySQL dependency is added, Spring Boot automatically sets up database configurations.

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2. Embedded Server

You do not need to install external servers separately.

Supported servers:

• Tomcat
• Jetty
• Undertow

Run application using:

mvn spring-boot:run

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3. Starter Dependencies

Spring Boot provides starter packages to simplify dependency management.

Examples:

• spring-boot-starter-web
• spring-boot-starter-data-jpa
• spring-boot-starter-security

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4. REST API Development

Spring Boot is excellent for creating RESTful APIs.

Example:

@RestController
public class HelloController {

    @GetMapping("/")
    public String hello() {
        return "Hello Spring Boot";
    }
}

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5. Production Ready Features

Spring Boot provides:

• Monitoring
• Health checks
• Metrics
• Logging

Using:

spring-boot-starter-actuator

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Spring Boot Architecture

Main layers:

1. Controller Layer
2. Service Layer
3. Repository Layer
4. Database Layer

Flow: Client → Controller → Service → Repository → Database

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Creating Your First Spring Boot Project

Step 1: Install Requirements

You need:

• Java JDK
• Maven
• IDE like IntelliJ IDEA or Visual Studio Code

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Step 2: Create Project

Use the official Spring Initializr:

Spring Initializr

Choose:

• Project: Maven
• Language: Java
• Dependencies: Spring Web

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Step 3: Run the Application

Main class:

@SpringBootApplication
public class DemoApplication {

    public static void main(String[] args) {
        SpringApplication.run(DemoApplication.class, args);
    }
}

Run:

mvn spring-boot:run

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Spring Boot Project Structure

src
 └── main
      ├── java
      │     └── com.example.demo
      │            ├── controller
      │            ├── service
      │            ├── repository
      │            └── model
      └── resources
            ├── application.properties
            └── static

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Database Integration

Spring Boot supports databases like:

• MySQL
• PostgreSQL
• MongoDB

Example MySQL configuration:

spring.datasource.url=jdbc:mysql://localhost:3306/demo
spring.datasource.username=root
spring.datasource.password=password

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Spring Boot Annotations

Important annotations:

Annotation	Purpose
@SpringBootApplication	Main application annotation
@RestController	Creates REST controller
@GetMapping	Handles GET requests
@PostMapping	Handles POST requests
@Service	Service layer
@Repository	Database layer
@Autowired	Dependency injection

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Advantages of Spring Boot

• Faster development
• Less boilerplate code
• Easy testing
• Scalable applications
• Large community support
• Enterprise-level security

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Common Uses of Spring Boot

Spring Boot is used for:

• Banking applications
• E-commerce websites
• Chat applications
• AI backend systems
• Cloud-native applications
• REST APIs
• Microservices

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Best Resources to Learn Spring Boot

Official Documentation

Spring Boot Documentation

Tutorials

• Baeldung Spring Boot Tutorials
• GeeksforGeeks Spring Boot Guide
• JavaTPoint Spring Boot Tutorial

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Conclusion

Spring Boot is a powerful framework for Java backend development. It simplifies complex configurations and helps developers quickly build scalable and production-ready applications. Learning Spring Boot is highly beneficial for students and developers preparing for software engineering roles, backend development, and full-stack projects.