Module 14: Enums and Annotations

Mini-Project: Ticket Workflow

Build a small ticket workflow using enums to model valid states and transitions.

Author

Java Learner Editorial Team

Reviewer

Technical review by Java Learner

Last reviewed

2026-04-17

Java version

Java 25 LTS

How this lesson was prepared: AI-assisted draft, manually edited for clarity, and checked against current Java documentation and runnable examples.

Learning goals

Project goal: Build a small ticket or task workflow with states like OPEN, IN_PROGRESS, BLOCKED, and DONE.

What to practice: Enum-driven state handling, transition validation, and maybe one custom annotation for methods that require a certain state.

Design aim: Invalid transitions should fail clearly instead of slipping through as silent bad strings.

Success check: The workflow should feel typed, readable, and hard to misuse accidentally.

Runnable examples

An enum makes valid states explicit

enum TicketState {
    OPEN, IN_PROGRESS, DONE
}

Expected output

Only the declared workflow states are valid.

Mini exercise

Implement three ticket states first, then add a guard that blocks moving from `DONE` back to `OPEN`.

Summary

Enums are excellent for workflow state modeling.
Annotations can add useful metadata around those transitions.
This project closes the intermediate track by combining type safety and clarity.

Next step

From here, you can move into the advanced track: concurrency, database access, Spring Boot, and larger capstones.

Sources used