Level Up to Java Spring Boot Developer at HCL

Follow this simple plan to move from Java Developer to a Spring Boot Developer. Build real skills using clear steps and one main project.

Weekly Hours: 10
Estimated Weeks: 8

Phases

Spring Boot Foundations

Learn basic Spring Boot concepts and project setup. Understand the flow of a Spring Boot application by building a simple web API.

2 weeks

Understand Spring Boot structure
Set up new Spring Boot project
Create REST endpoints
Test your API

Initialize project (Spring Initializr)
Write REST Controller (get user details)
Use application.properties (custom port)
Write simple JUnit test

Official Spring Boot Guides
Spring Initializr
JUnit Documentation

Demo basic Spring Boot API with one REST endpoint
Document project setup steps

Data Persistence

Connect your app to a database and perform CRUD (Create, Read, Update, Delete) with Java Persistence API. Learn to structure data using entities and repositories.

2 weeks

Set up database connection
Write CRUD operations
Use Spring Data JPA
Test data access

Create Entity class (User.java)
Write Repository interface (UserRepository)
Configure datasource (H2 database)
Add JPA tests (save/find user)

Spring Data JPA Guides
H2 Database Reference
Basic SQL Tutorial

CRUD API working with in-memory DB
Tests for repository functions

State and Forms

Handle form input and validation. Add state to your APIs and manage user input effectively. Ensure good error handling for forms.

2 weeks

Create forms in frontend or Postman
Validate input data
Handle errors neatly
Document endpoints

Use @Valid annotation (email/password validation)
Return error messages (user not found)
Document API endpoints (Swagger or manual doc)

Spring Validation Guide
Swagger or OpenAPI Tools
Postman

Validated forms with error responses
API documentation with 3 endpoints, including sample request/responses

Testing and CI

Write automated tests and set up simple Continuous Integration. Make sure your project quality is clear and trusted.

1 weeks

Write and run tests
Use a CI tool
Show test status badge

Write integration test (test all user flows)
Add CI workflow (GitHub Actions)
Fix test errors

JUnit Testing Guides
GitHub Actions Tutorials

All key API paths tested
Visible CI badge in your project README

Deployment and Polish

Prepare your project for sharing with others. Deploy your app, write clear instructions, and make it ready to show in a real interview.

1 weeks

Deploy Spring Boot app
Write clear README
Share demo link

Deploy on free cloud (Render, Heroku)
Summarize setup in README
Invite friend to test

Heroku or Render Guides
Sample Project READMEs

Live app link running
Full instructions and screen demo shared

Weekly Plan

Week	Focus	Why	Tasks	Deliverables
1	Spring Boot Setup and Basics	Learn Spring Boot and fast project setup.	Read introductory Spring Boot guide, Generate starter app (Spring Initializr), Create simple REST controller (Hello World), Customize port in application.properties	HelloWorld Spring Boot app, Setup steps documented
2	Building First REST Endpoint	Practice API building and basic testing.	Add REST endpoint (GET user by ID), Write JUnit test for endpoint, Test API with Postman	REST endpoint demo, Passing unit test
3	Data Persistence Foundations	Connect to a database and store data.	Set up H2 database, Create Entity class (User), Set up Repository interface	User entity created, Repository connects to database
4	CRUD Operations	Save, get, update, and delete data.	Write CRUD endpoints (User create/read/update/delete), Test each operation (Postman), Add repository tests (JUnit)	All CRUD endpoints work, Basic data tests written
5	Input Validation and Error Handling	Check input data and handle errors cleanly.	Add validation to User input, Return custom errors (user not found), Write tests for error cases	Validated endpoints, Error handling works
6	API Documentation and Forms	Make API easy to use and understand.	Document endpoints (Swagger or markdown), Build simple frontend form or use Postman collection, Share sample requests	API documented, Sample form or collection
7	Testing and Continuous Integration (CI)	Prove code works and is reliable.	Write integration tests (all user flows), Set up GitHub Actions workflow, Add CI badge to README	Integration tests pass, CI status visible on GitHub
8	Deployment and Showcasing	Publish and share your finished app.	Deploy app to Heroku or Render, Write and polish project README, Record a screen demo (optional)	Live deployment link, Complete README

Daily Plan

Monday

Read Spring Boot or database guide
Review last week's code

Tuesday

Write or update REST endpoint
Test changes locally

Wednesday

Add new feature or validation
Write unit or integration tests

Thursday

Fix bugs from tests
Improve documentation or code comments

Friday

Try full user flow (end-to-end test)
Push code to GitHub and check CI