exercise2

Exercise 2

Run and hack on a Quarkus project

In this exercise, we will run a Quarkus project and play with it to get familiar with some basic commands and constructs!

0. Start Quarkus in Dev mode

./mvnw quarkus:dev

keep this running in a separate terminal window throughout this exercise!

1. Getting parameters

Have a look at the endpoint that is declared in GreetingResource:

@Path("/greeting/{name}")

Note how we declare and access the "name" parameter using the @PathParam annotation!

2. Write a new JSON based method

Create a new method called "multipleGreetings" that sends a list of greetings in different languages, as JSON. Below is some basic code to get you started.

// create a list to show some data
private List<String> greetingsInMultipleLangs = new ArrayList<String>() {{
    add("Hello");
    add("Salut");
    add("Hola");
    add("Nǐ hǎo");
}};
   
@GET
@Produces(MediaType.APPLICATION_JSON)
@Path("/multiple")
public List<String> multipleGreetings() {
    return greetingsInMultipleLangs;
}

Quarkus REST Guide

Now when you go to: http://localhost:8080/hello/multiple you should see some JSON. We suggest using Firefox as it has a nice built in JSON response viewer.

3. Explore CDI (dependency injection)

You probably noticed a GreetingService.java file in the same dir as GreetingResource.java. The service was injected in using this annotation:

@Inject
GreetingService service; 

And was used later in a method like this: service.greeting(name)

Go and change the return value of greeting method in the service and hit the /greeting/{name} endpoint, see what happens.

4. Create new endpoint

Add another method to get a single value from greetingsInMultipleLangs created in step #2 above. Here's a hint:

  @GET
  @Path("/{id}")
  public String getOne(@PathParam("id") Long id) {

...

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