Introduction

Spring Boot is an open-source Java-based framework used to create stand-alone, production-grade Spring-based applications with minimal effort. It simplifies the development process by providing a set of conventions and defaults, reducing the need for extensive configuration.

Key Features of Spring Boot

Auto-Configuration: Automatically configures your Spring application based on the dependencies you have added to the project.
Standalone: Spring Boot applications can run independently without requiring an external application server.
Production-Ready: Includes features like metrics, health checks, and externalized configuration to help you get your application ready for production.
Opinionated Defaults: Provides a set of default configurations to get you started quickly, but allows for customization as needed.
Embedded Servers: Comes with embedded servers like Tomcat, Jetty, and Undertow, making it easy to deploy your application.

Why Use Spring Boot?

Simplified Configuration: Reduces the complexity of configuring Spring applications.
Rapid Development: Speeds up the development process with its opinionated approach and auto-configuration.
Microservices: Ideal for building microservices due to its lightweight and modular nature.
Community Support: Backed by a large and active community, providing extensive documentation and support.

How Spring Boot Works

Spring Boot leverages the Spring Framework's core features while adding its own layer of functionality. Here's a high-level overview of how it works:

Starter POMs: Spring Boot provides a set of starter POMs (Project Object Models) that include common dependencies for various functionalities, such as web development, data access, and security.
Auto-Configuration: Based on the dependencies present in your project, Spring Boot automatically configures the necessary beans and settings.
Embedded Servers: Spring Boot applications can run on embedded servers, eliminating the need for a separate application server.
Spring Boot CLI: A command-line interface that allows you to quickly prototype and run Spring Boot applications.

Practical Example

Let's create a simple Spring Boot application to understand its basic structure and functionality.

Step 1: Setting Up the Project

Create a new Maven project.
Add the Spring Boot Starter Parent to your pom.xml:

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.5.4</version>
</parent>

Add the Spring Boot Starter Web dependency:

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
</dependencies>

Step 2: Creating the Main Application Class

Create a new Java class named Application.java:

package com.example.demo;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

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

Step 3: Creating a REST Controller

Create a new Java class named HelloController.java:

package com.example.demo;

import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class HelloController {

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

Step 4: Running the Application

Run the Application.java class. Your Spring Boot application will start, and you can access the REST endpoint at http://localhost:8080/hello.

Summary

In this section, we covered the basics of Spring Boot, including its key features, benefits, and how it works. We also walked through a simple example to demonstrate how to set up and run a Spring Boot application. This foundational knowledge will prepare you for more advanced topics in the subsequent modules.

What is Spring Boot?

Introduction

Key Features of Spring Boot

Why Use Spring Boot?

How Spring Boot Works

Practical Example

Step 1: Setting Up the Project

Step 2: Creating the Main Application Class

Step 3: Creating a REST Controller

Step 4: Running the Application

Summary

Spring Boot Course

Module 1: Introduction to Spring Boot

Module 2: Spring Boot Basics

Module 3: Building RESTful Web Services

Module 4: Data Access with Spring Boot

Module 5: Spring Boot Security

Module 6: Testing in Spring Boot

Module 7: Advanced Spring Boot Features

Module 8: Deploying Spring Boot Applications

Module 9: Performance and Monitoring

Module 10: Best Practices and Tips