Online Spring Boot course to understand the framework and use it with sound judgement
Build layered applications and discover what happens between an HTTP request, business logic, the transaction and the database.
- Layered architecture
- Unit and integration testing
- Security by design
What should an online Spring Boot course teach?
It should connect HTTP requests, application rules, data storage and tests in a working Java application. Learn what each layer does, inspect failures and practise configuration. KINTAVOR combines these topics in its Java backend course; Java runs on your own computer.
Follow one request through the application
Use a small booking API as a learning example. A controller receives the request, a service checks the booking rule and a repository handles storage. Trace the return journey as well: status code, response body and any error message.
Start with a single endpoint and an in-memory result. Add persistence only once you can test the endpoint. The Spring guides below demonstrate a REST service and web-layer tests; check the prerequisites of each guide against the version used by your project.
- Keep business rules out of the controller so they can be tested separately.
- Test a valid request and a rejected request before adding another endpoint.
- Keep passwords and connection details out of source control.
Reference material: Spring: building a RESTful web service · Spring: testing the web layer
Beyond creating a project and adding annotations
Spring Boot makes it easier to start an application, but it does not decide where to put a business rule, how to define a transaction boundary or which data an endpoint should expose. The course separates convenience from design so that you can justify each layer.
First, you will study the Spring container, dependency injection, configuration and the component creation lifecycle. You will then explore Boot's structure, its starters, auto-configuration and environment profiles.
- Controllers focused on the HTTP contract.
- Services that express use cases and transactional boundaries.
- Repositories focused on persistence and queries.
- DTOs separated from entities when the contract requires it.
Persistence without treating JPA as magic
Linking entities is only part of the work. You will analyse identity, cardinality, association fetching, cascades, queries, pagination, sorting and the cost of accessing data. You will also compare JPA with SQL and JDBC to recognise when an abstraction helps and when it hides a problem.
The exercises include common errors: N+1 queries, updates outside a transaction, incomplete validation and conflicts between the API model and the relational schema.
An observable and protected API
You will learn to validate requests, return consistent errors and document contracts with OpenAPI. Spring Security is presented as a sequence of decisions: authentication, authorisation, roles, permissions, credential handling and protection of each endpoint.
Logging, metrics and Actuator let you observe behaviour without revealing secrets or personal data. The OWASP modules help you review inputs, object-level authorisation, information exposure and insecure configuration.
- JWT with its limits and threats explained.
- Error messages that are useful to the client and safe for production.
- Separate configuration for development, testing and deployment.
- Secrets kept outside the repository and documented rotation.
Tests that support the architecture
Unit tests isolate rules; web tests verify HTTP contracts; persistence tests check queries; and integration tests connect the necessary parts. Not everything needs to start with the full Spring context.
Each project includes a test strategy, initial data and error cases. The aim is to detect regressions in important decisions, rather than achieve a decorative percentage.
A process you can repeat for every challenge
Understanding, implementing and checking are parts of the same task.
- 01
Contract
Define inputs, outputs, errors and permissions.
- 02
Use case
Express the rule independently of HTTP details.
- 03
Persistence
Design observable transactions and queries.
- 04
Evidence
Test the behaviour and document the endpoint.
Frequently asked questions
Specific answers about this learning pathway.
Does this course only teach Spring Boot?
No. The full pathway covers Java, SQL, HTTP and testing before exploring Spring in depth. This reduces reliance on recipes and makes errors easier to diagnose.
Which version of Spring Boot is used?
The distribution includes a centralised version matrix verified against official documentation. A stable release line compatible with the course JDK is selected, and an introduction to migration is included.
Is Spring Security taught?
Yes. It covers authentication, authorisation, roles, permissions, JWT, security tests and API risks. JWT is not presented as a universal solution.
Does it include microservices?
It includes a responsible introduction. First, you consolidate a modular application; then you study the costs, boundaries and signs that may justify separating services.
Can I run the projects without Docker?
Yes. Docker is optional. You can run Java, Maven and PostgreSQL directly on your computer using the documented alternative.
Does a successful application start prove that my API works?
No. A start-up check shows that the application can load. You also need tests for request handling, validation and expected responses, followed by checks of the important paths through storage and application rules.
Sources and further reading
- Spring: building a RESTful web service — A small HTTP endpoint and JSON response in Spring. Checked 2026-09-15.
- Spring: testing the web layer — Examples of testing a Spring application and its web layer. Checked 2026-09-15.
Develop this skill in the full Java backend course
Follow the programme, exercises and projects at your own pace. Review the current price and twelve-month access terms before enrolling.
KINTAVOR provides private training. Its certificate is proprietary and unofficial. Employment, salary and success in recruitment processes are not guaranteed. Third-party brands are used for descriptive purposes only, without affiliation.
Content updated: 2026-09-15.