blog-manager

blog-manager is a REST API for a blogging platform, handling authentication, authorization, and content management for posts and comments. Any frontend is a thin client that simply consumes the API — all business logic, validation, and security live on the backend.

Authentication & security

Users authenticate with a username/password flow through Spring Security, backed by JJWT-issued access tokens and single-use refresh tokens persisted per user. A custom JwtAuthFilter validates tokens on every request, while a RestAuthEntryPoint returns structured JSON error responses instead of default redirects when authentication is missing or invalid. A CurrentUserProvider component resolves the authenticated user from the security context for use across services.

Posts & comments

Posts belong to authors through a Post → User relationship, and comments extend this to a Post ↔ Comment ↔ User structure, letting users comment on any post while only modifying their own contributions. Ownership is enforced at the service layer for every mutating operation — updating or deleting a post or comment checks the requesting user’s ID against the resource’s author before proceeding. All entity IDs are String-typed UUIDs generated at persistence time.

Error handling & API design

A centralized GlobalExceptionHandler maps domain exceptions — not found, forbidden, duplicate user, invalid/expired tokens, malformed JSON, and validation failures — into a consistent ApiResponse shape with the appropriate HTTP status codes. The API is fully documented with OpenAPI/Swagger UI, including built-in Bearer JWT authorization support directly from the docs UI.

Testing

The service and repository layers are covered by unit and integration tests, with Testcontainers spinning up a real PostgreSQL instance for repository and service integration tests rather than relying on mocks or an in-memory database.

Tech stack

Built with Spring Boot 4 and Java 25, using Spring Security for auth, JJWT for token generation and validation, and JPA/Hibernate over PostgreSQL for persistence. Validation is handled with Spring Validation, and the API is documented via springdoc-openapi.