./gradlew test --tests "*CinemaWiringTest"

> Task :test
CinemaController -> CinemaService -> CinemaRepository
BUILD SUCCESSFUL

phase-0-startJava delta kataBUILD SUCCESSFUL

phase-1-start/api/v1/cinemasADR-001

phase-1-donecurl transcriptwiring test

phase-2a-previewV1__schema.sqlEXPLAIN

repo must prove thingsTestsTagsADRsTranscripts

javatutorial.imdmp.com

Palabas API Course

Learn modern Java backend development by building one real Spring Boot API from scratch. No toy CRUD, no frontend detour, no fake production claims.

Start the path See the proof model

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Built for JVM engineers

A course site over a real repo, not a sandbox fantasy.

The site teaches. The Palabas repo proves. Every lesson names a concrete task, the command that verifies it, and the artifact that should exist afterward.

MVP progress is local to your browser. Hosted graders, GitHub OAuth, and AI hints wait until at least Phase 1 is fully teachable.

First public slice

Published lessons

0 complete locally

Module 0 / Lesson 0.1

Java 25 for Kotlin Developers

Build the translation table you will use for the rest of the course.

Module 1 / Lesson 1.1

Generate the Spring Skeleton

Create the smallest Spring Boot app that can carry the rest of the curriculum.

Module 1 / Lesson 1.3

Constructor Injection and the Wiring Test

Wire controller to service to repository without hiding dependencies.

Module 1 / Lesson 1.6

ADR-001: Layers and Versioning Stance

Commit the API versioning decision before future endpoints multiply.

Module 1 / Checkpoint

Phase 1 Boss Fight: Prove the API Skeleton

Finish Phase 1 with tests, curl output, ADR-001, and a tag.

Module 2A / Lesson 2A.0

Preview: Schema First

See why the database model comes before JPA entities.

Module 2A / Lesson 2A.1

Cinema and Screen Schema

Create the first Flyway migration for cinemas and screens before any JPA entity exists.

Module 2A / Lesson 2A.2

Movie and Showtime Schema

Model showtimes as booking facts with stored occupancy windows.

Module 2A / Lesson 2A.3

Postgres Exclusion Constraint

Enforce no overlapping showtimes per screen with a GiST exclusion constraint.

Module 2A / Lesson 2A.4

Indexes and EXPLAIN

Add indexes for known reads and capture the planner story without forcing a fake win.

Module 2A / Checkpoint

Phase 2A Boss Fight: Let SQL Prove It

Finish SQL-first by proving constraints, notes, time handling, ERD, seed data, and EXPLAIN artifacts exist together.

Module 2B / Lesson 2B.1

Hibernate Mental Model Tests

Map entities after the schema exists and prove Hibernate behavior in labeled tests.

Module 2C / Lesson 2C.1

N+1, Fetch Strategies, Pagination, and Geo Query

Cause the N+1 problem on purpose, fix it three ways, and show where fetch joins become wrong.

Module 2C / Checkpoint

Phase 2B/2C Boss Fight: Prove Persistence Performance

Finish the Hibernate and query-performance module with tests, transcripts, and article links.

Module 3 / Lesson 3.1

Postgres and Oracle Invariants

Open the Oracle lane and keep the no-overlap invariant true without Postgres-only features.

Module 4 / Lesson 4.1

API Hardening With DTOs and ProblemDetail

Turn the tutorial API into a merge-ready boundary with validation, ProblemDetail, and architecture tests.

Module 5 / Lesson 5.1

Spring Security Resource Server

Protect writes with a real resource-server filter chain while keeping public reads simple.

Module 5 / Checkpoint

Phase 5 Checkpoint: Application Readiness

Confirm Phases 0-5 form an application-ready backend story before observability and deployment.

Module 6 / Lesson 6.1

Observability as a Debugging Story

Add correlation IDs, structured logs, Prometheus metrics, and cache evidence that answer real debugging questions.

Module 7 / Lesson 7.1

Ship a Read-Only Demo Without Fake Public Writes

Create the CI, image, profile, and runbook for an ARM-hosted read-only Palabas API demo.

Module 8 / Lesson 8.1

The Interview Map

Map senior-backend interview claims to the exact commits, tests, ADRs, docs, and articles that prove them.

Module 8 / Checkpoint

Final Checkpoint: Evidence-Backed Java Backend Course

Close M7 with observability, shipping, interview mapping, final articles, and a release/deploy evidence check.

Extras / Lesson S.1

Supplement: Java Version Discipline

Make the project Java version boring: one local JDK pin, one Gradle toolchain, and one CI provider.

Course map

Modules that end in proof

Open full path

Module 0

Java Delta

A committed kata file with notes on records, Optional, streams, sealed switch, and virtual threads.

Module 1

Spring Skeleton

A wiring test, curl transcript, ADR-001, and a phase-1-done tag.

Module 2A

SQL First

Constraints, EXPLAIN transcripts, schema notes, and time notes.

Module 2B

Hibernate Mental Model

Educational tests with annotated SQL logs.

Module 2C

Query Performance

Broken and fixed query-count tests plus a stable paginated endpoint.

Module 3

Invariant Testing + Oracle

Concurrent overlap tests pass on both databases.

Module 4

API Hardening

ArchUnit and error-path tests keep the API honest.

Module 5

Security

Five request outcomes are asserted through the real filter chain.

Module 6

Observability

Two transcripts reconstruct failures and slow paths from telemetry alone.

Module 7

Shipping

Green CI, live Swagger, and v1.0.0 tag.

Module 8

Interview Mapping

INTERVIEW.md points to concrete artifacts instead of claims.

Extras

Supplements

Each supplement turns a real workflow failure into a repeatable project convention.