Introduction to Spring Boot

What is Spring Boot?

Spring Boot is a framework that simplifies the development of Java applications, particularly web applications. It provides a set of tools and conventions that make it easier to create stand-alone, production-grade applications.

Key Features of Spring Boot

  1. Autoconfiguration: Spring Boot automatically configures your application based on the dependencies you’ve added.

  2. Standalone: Spring Boot applications can be run without an external web server.

  3. Opinionated: It provides a set of ‘opinions’ (default configurations) that can be easily overridden.

Creating a Spring Boot Project

We’ll use Spring Initializr to create our first Spring Boot project:

  1. Go to https://start.spring.io/

  2. Choose: - Project: Gradle - Groovy - Language: Java - Spring Boot: (Latest stable version) - Project Metadata: Fill in Group, Artifact, etc. - Dependencies: Add ‘Spring Web’ for now

  3. Click ‘Generate’ to download the project

  4. Extract the ZIP file and open it in IntelliJ IDEA

Project Structure

A typical Spring Boot project structure with Gradle looks like this:

my-project/
├── src/
│   ├── main/
│   │   ├── java/
│   │   └── resources/
│   └── test/
├── build.gradle
├── settings.gradle
└── README.md

  • src/main/java/: Contains your Java source code

  • src/main/resources/: Contains static resources and configuration files

  • src/test/: Contains your test code

  • build.gradle: Gradle configuration file that manages dependencies and build process

  • settings.gradle: Defines project-level settings

Running Your Application

To run your Spring Boot application:

  1. Open the main class (annotated with @SpringBootApplication)

  2. Right-click and select ‘Run’

Alternatively, you can use the Gradle wrapper in the terminal:

./gradlew bootRun

Your application will start, typically on port 8080.

Build Process

Gradle handles the build process for your Spring Boot application. Some common Gradle commands:

  • ./gradlew build: Compiles the project and runs tests

  • ./gradlew clean: Removes the build directory

  • ./gradlew test: Runs the tests

Next Steps

In the following sections, we’ll explore how to create REST controllers, handle HTTP requests, and interact with databases using Spring Boot.