Spring Boot Setup

Setting up a Spring Boot project takes under five minutes. You use a tool called Spring Initializr to generate a ready-to-run project, then open it in your IDE.

What You Need Before Starting

• Java JDK 17 or higher — Spring Boot 3.x requires Java 17+
• Maven or Gradle — build tools that manage dependencies
• IDE — IntelliJ IDEA (recommended), Eclipse, or VS Code
• Internet connection — to download dependencies

Check Your Java Version

Open a terminal and run:

java -version

You should see version 17 or above. If not, download the latest JDK from adoptium.net.

Step 1 — Generate a Project with Spring Initializr

Go to start.spring.io in your browser. This website generates a project skeleton for you.

┌────────────────────────────────────────────┐
│           Spring Initializr                │
│                                            │
│  Project:   Maven                          │
│  Language:  Java                           │
│  Spring Boot: 3.x (latest stable)          │
│                                            │
│  Group:     com.estudy247                  │
│  Artifact:  demo                           │
│  Packaging: Jar                            │
│  Java:      17                             │
│                                            │
│  Dependencies:  Spring Web                 │
│                                            │
│  [ Generate ]                              │
└────────────────────────────────────────────┘

Click Generate. A ZIP file downloads to your computer.

Step 2 — Open the Project in Your IDE

1. Unzip the downloaded file
2. Open IntelliJ IDEA
3. Click File → Open and select the unzipped folder
4. IntelliJ detects it as a Maven project and downloads all dependencies automatically

Step 3 — Run the Application

Open the main class — it is named DemoApplication.java. Click the green Run button or press Shift + F10.

You will see output in the console ending with:

Tomcat started on port 8080
Started DemoApplication in 1.4 seconds

Your Spring Boot app is running on http://localhost:8080.

The Main Class Explained

@SpringBootApplication                    ← Magic annotation that enables everything
public class DemoApplication {

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

}

@SpringBootApplication combines three annotations into one:

@SpringBootApplication
    │
    ├── @Configuration       ← This class defines beans
    ├── @EnableAutoConfiguration  ← Auto-configure based on libraries present
    └── @ComponentScan       ← Scan this package for components

Understanding pom.xml

Maven uses a file called pom.xml to manage dependencies. Your generated file includes:

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>3.x.x</version>   ← Spring Boot version
</parent>

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
        <!-- No version needed — parent manages it -->
    </dependency>
</dependencies>

The parent POM manages all version numbers. You add starters and Spring Boot picks compatible versions automatically.

Common Starters and What They Include

Starter Name                    What It Adds
────────────────────────────    ──────────────────────────────
spring-boot-starter-web         Tomcat, Spring MVC, JSON support
spring-boot-starter-data-jpa    Hibernate, Spring Data, JPA
spring-boot-starter-security    Spring Security, auth filters
spring-boot-starter-test        JUnit, Mockito, AssertJ
spring-boot-starter-validation  Bean Validation (Hibernate Validator)

Summary

• Use start.spring.io to generate a Spring Boot project in seconds
• Java 17+ and Maven are the minimum requirements for Spring Boot 3.x
• @SpringBootApplication starts auto-configuration and component scanning
• Starters bundle all related dependencies so you add just one line
• The embedded Tomcat server starts on port 8080 by default