Veebirakenduse projekt (ITI0302)

Goal of today

• By the end of this lab:
  • A Spring Boot project runs on your machine and answers REST calls
  • Your first merge request is merged in GitLab
  • You have seen Individual assignment 1 — after today's lecture you can write all the code for it
• Deployment comes later: server + Docker next week, CI the week after
• Stuck at any step → raise your hand, that's what the lab is for

Check your tools

• Java: java -version → 21 or newer (latest LTS = 25)
• IntelliJ IDEA — Ultimate is free with your student licence
• Git: git --version
• You can log in to GitLab (gitlab.cs.taltech.ee) with your uni account

GitLab repo

• Create a project named iti0302-2026 (visibility: private)
• Add your SSH key to your GitLab profile (Settings → SSH Keys)
  • No key yet? ssh-keygen -t ed25519 and copy the contents of ~/.ssh/id_ed25519.pub
  • This key is for GitLab — server keys come next week
• Clone the repo to your machine

Create the project

• IntelliJ: File → New → Project → Spring Boot (or use https://start.spring.io/ and unzip into your repo)
• Choose: Maven or Gradle (your pick), Java, latest LTS
• Dependency: Spring Web — nothing else needed today
• Open it, let dependencies download, run the main method
• You should see Tomcat start on port 8080

Hello World

@RestController
public class HelloController {

    @GetMapping("/")
    public String hello() {
        return "Hello ITI0302";
    }
}

• Rerun the application (rerun after every change)
• Open http://localhost:8080 in the browser

First merge request

• git checkout -b feature/hello-world
• Commit, push, open a merge request in GitLab, merge it
• This is the workflow for everything in this course from now on:
  • branch → commit → merge request → merge
  • Nothing goes straight to main

Individual assignment 1

• Full assignment deck is in Moodle — read it now, we'll walk through it
• Due: week 5 Sunday 23:59, 10 points
• Your variant comes from the last digit of your student code
• The full task: REST app + Docker on your server + CI pipeline
• Today you can already build the code part — everything except /api/version:
  • GET /api/{resource} — list, 200
  • GET /api/{resource}/{id} — 200 / 404
  • POST /api/{resource} — 201 + created object
  • DELETE /api/{resource}/{id} — 204 / 404
  • GET /api/{resource}?name=x — filtered list
• GET /api/version needs the CI pipeline — we wire it up in the week 3 lab

Pattern: in-memory storage

• No database needed for A1 — a map in memory is enough:

@RestController
@RequestMapping("/api/employees")
public class EmployeeController {

    private final Map<Long, Employee> storage = new HashMap<>();
    private final AtomicLong ids = new AtomicLong(1);

    @GetMapping
    public List<Employee> getAll() {
        return new ArrayList<>(storage.values());
    }
}

• Lab example uses employees — your A1 resource is different, adapt it
• One controller class is fine for A1; layered architecture comes later

Status codes

@PostMapping
@ResponseStatus(HttpStatus.CREATED)          // 201
public Employee create(@RequestBody Employee e) { … }

@GetMapping("/{id}")
public Employee get(@PathVariable Long id) {
    Employee e = storage.get(id);
    if (e == null) {
        throw new ResponseStatusException(HttpStatus.NOT_FOUND);  // 404
    }
    return e;
}

• DELETE: @ResponseStatus(HttpStatus.NO_CONTENT) → 204

Test it

• Create a file requests.http in your repo and run each request from IntelliJ:

POST http://localhost:8080/api/employees
Content-Type: application/json

{ "name": "Siim" }

###
GET http://localhost:8080/api/employees

###
GET http://localhost:8080/api/employees/999

###
DELETE http://localhost:8080/api/employees/1

• Check the status codes, not just the bodies — 201, 200, 404, 204

You are done when

• All A1 endpoints except /api/version answer correctly on your machine — right paths, right status codes, right JSON types
• Everything reached main through merged merge requests
• requests.http is in the repo, covering every endpoint
• Ahead of everyone? Read the Docker basics — next week this app goes onto a real server

Next week

• You get your own server — SSH access, Linux basics
• Bring your laptop
• Submit your SSH public key in Moodle (assignment "SSH key") before next week's lab
  • You already know how to make one — servers are provisioned from what's submitted
  • Submit the .pub file contents, never the private key