Start Learning
Javaneer
Back to the Spring path
🌐
Module 2

Building Web APIs

Ship a REST API the right way.

Turn BookVault into a real HTTP API. The Spring MVC request pipeline, REST controllers, request and response bodies, validation, clean error responses with ProblemDetail, OpenAPI docs, and calling other services.

7 Lessons in this stage1 h 48 min
Start the first lesson

Lessons in this stage

  1. 01

    Spring MVC & the Request Flow

    Intermediate

    The DispatcherServlet front controller and the journey of a request from HTTP arrival to JSON response.

    16 min
  2. 02

    REST Controllers & Mapping

    Intermediate

    @RestController, mapping URLs and HTTP methods, path variables and query params, and ResponseEntity.

    18 min
  3. 03

    Request & Response Bodies

    Intermediate

    DTOs and records, @RequestBody, JSON (de)serialization with Jackson, and content negotiation.

    16 min
  4. 04

    Validating Input

    Intermediate

    Bean Validation with @Valid and constraint annotations, and turning failures into helpful responses.

    16 min
  5. 05

    Exception Handling & ProblemDetail

    Intermediate

    @ExceptionHandler, @ControllerAdvice, and standard RFC 9457 ProblemDetail error responses.

    16 min
  6. 06

    Documenting with OpenAPI

    Beginner

    Generate live, interactive API docs with springdoc-openapi and Swagger UI - for free.

    12 min
  7. 07

    Calling Other APIs

    Intermediate

    Consuming HTTP services with the modern RestClient (and when to reach for WebClient).

    14 min

Ready to test yourself?

Take the stage assessment to check your mastery. Pass it to earn a stage badge toward your Javaneer certificate.

Take the assessment