Project structure walkthrough in Spring Boot

Introduction

A clear project structure helps you find and organize your code easily. It makes your Spring Boot app neat and simple to work on.

When starting a new Spring Boot application to keep code organized.

When adding new features and you want to know where to put files.

When working with a team so everyone understands the project layout.

When debugging or updating code and you need to find files quickly.

When preparing your app for deployment or sharing with others.

Syntax

Spring Boot

src
 ├── main
 │    ├── java
 │    │    └── com.example.project
 │    │         ├── controller
 │    │         ├── service
 │    │         ├── repository
 │    │         └── Application.java
 │    └── resources
 │         ├── application.properties
 │         └── static
 └── test
      └── java
           └── com.example.project
                └── ApplicationTests.java

src/main/java holds your Java code organized by packages.

src/main/resources contains config files and static assets like images or CSS.

Examples

Controllers handle web requests and responses.

Spring Boot

src/main/java/com/example/project/controller/UserController.java

Services contain business logic and operations.

Spring Boot

src/main/java/com/example/project/service/UserService.java

Repositories manage data access and database queries.

Spring Boot

src/main/java/com/example/project/repository/UserRepository.java

Configuration settings for your Spring Boot app.

Spring Boot

src/main/resources/application.properties

Sample Program

This is the main class that starts your Spring Boot app. It lives in the base package.

Spring Boot

package com.example.project;

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);
    }
}

Important Notes

Keep your package names clear and consistent to avoid confusion.

Place test classes in src/test/java mirroring your main code packages.

Use resources/static for files like images, CSS, and JavaScript that your app serves.

Summary

Spring Boot projects have a standard folder layout to organize code and resources.

Main Java code goes under src/main/java with packages like controller, service, and repository.

Configuration and static files go under src/main/resources.