https://www.baeldung.com/quarkus-io

Method 1 create a new Quarkus Project using mvn command

1. Create Quarkus Project using Maven

mvn io.quarkus:quarkus-maven-plugin:0.13.1:create \
    -DprojectGroupId=com.dessertmenu.quarkus \
    -DprojectArtifactId=quarkus-project \
    -DclassName="com.dessertmenu.quarkus.DessertMenuResource" \
    -Dpath="/dessertmenu"

You should get this:

.
├── quarkus-project
│   ├── mvnw
│   ├── mvnw.cmd
│   ├── pom.xml
│   └── src
│       ├── main
│       │   ├── docker
│       │   │   ├── Dockerfile.jvm
│       │   │   └── Dockerfile.native
│       │   ├── java
│       │   │   └── com
│       │   │       └── dessertmenu
│       │   │           └── quarkus
│       │   │               └── DessertMenuResource.java
│       │   └── resources
│       │       ├── application.properties
│       │       └── META-INF
│       │           └── resources
│       │               └── index.html
│       └── test
│           └── java
│               └── com
│                   └── dessertmenu
│                       └── quarkus
│                           ├── DessertMenuResourceTest.java
│                           └── NativeDessertMenuResourceIT.java

2. Open the Project in an IDE

(Intellij ->New ->Project from Existing Sources) The content of the DessertMenuResource class:

package com.dessertmenu.quarkus;

import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.core.MediaType;

@Path("/dessertmenu")
public class DessertMenuResource {

    @GET
    @Produces(MediaType.TEXT_PLAIN)
    public String hello() {
        return "hello";
    }
}

Change The hello method to this:

    @GET
    @Produces(MediaType.TEXT_PLAIN)
    public String listFruit() {
        return "You can order : Banana, Apple, or Strawberry as desert.";
    }

3. Launch the Quarkus Project

Run this command

cd quarkus-project/
./mvnw compile quarkus:dev:

4. We have Hot Reload

When running in development mode (./mvn compile quarkus:dev), Quarkus provides a hot-reload capability. In other words, changes made to Java files or to configuration files will a>

5. Call the REST Endpoint

The REST endpoint should be exposed at localhost:8080/hello.
In a new terminal (tab)

Let’s test it with the curl command:

curl localhost:8080/dessertmenu

Expect

You can order : Banana, Apple, or Strawberry as desert.

6. adding more API functionality to the project

Create a DessertMenuService class in the same package:

package com.dessertmenu.quarkus;

import javax.enterprise.context.ApplicationScoped;

@ApplicationScoped
public class DessertMenuService {

  public String orderDesert(String fruit){
    return "You have ordered: " + selectDesert(fruit);
  }

  private String selectDesert(String fruit){
    String dessert;
    switch(fruit.toUpperCase()){
      case "BANANA" :
        dessert ="Banana Split";
        break;
      case "APPLE" :
        dessert ="Apple Pie";
        break;
      case "STRAWBERRY" :
        dessert ="Strawberries and Creame";
        break;
      default:
        dessert=fruit;
    }
    return dessert;
  }
}

Edit the DessertMenuResource class, injecting the DessertMenuService and add a new method:

    @Inject
    DessertMenuService dessertMenuService;

    @GET
    @Produces(MediaType.APPLICATION_JSON)
    @Path("/order/{fruit}")
    public String orderDesert(@PathParam("fruit") String fruit) {
        return dessertMenuService.orderDesert(fruit);
    }
    

To test our new endpoint:

curl localhost:8080/dessertmenu/order/Apple

Expect

You have ordered: Apple Pie

Edit the application.properties file and add one more key:

dailyspecial=with icecream or fresh cream

Edit the DessertMenuService to use our new property, add this code:

  @ConfigProperty(name = "dailyspecial")
  private String dailyspecial;


  public String orderSpecialOfTheDay(String fruit){
    return "You have ordered: " + selectDesert(fruit) + " "+dailyspecial;
  }
  

Edit the DessertMenuResource class to call the new service method add this code:

    @GET
    @Produces(MediaType.APPLICATION_JSON)
    @Path("/orderspecial/{fruit}")
    public String orderSpecialOfTheDay(@PathParam("fruit") String fruit) {
        return dessertMenuService.orderSpecialOfTheDay(fruit);
    }

To test our new endpoint:

curl localhost:8080/dessertmenu/orderspecial/Apple

Expect

You have ordered: Apple Pie with icecream or fresh cream

7. Edit Unit Test

Before we can build this project we need to incorporate our changes in our unit tests
Open unit test class : DessertMenuResourceTest change body value

    @Test
    public void testHelloEndpoint() {
        given()
          .when().get("/dessertmenu")
          .then()
             .statusCode(200)
             .body(is("You can order : Banana, Apple, or Strawberry as desert."));
    }

8. Package the application

First stop Quarkus Application running in the first terminal tab To package the application run:

./mvnw package

9.Running the packaged Application

To run the packaged application:

java -jar target/quarkus-project-1.0-SNAPSHOT-runner.jar

curl localhost:8080/dessertmenu
curl localhost:8080/dessertmenu/order/Apple
curl localhost:8080/dessertmenu/orderspecial/Apple

10. Using a Native Image

You need to install GraalVM to do this The instalation of GraalVM is beyond the scope of this document but we do provide instructions to work with native Images after you have installed GraalVM
Next, we’ll produce a native image of our application.
A native image will improve start-up time and time to first response. In other words, it contains everything it needs to run, including the minimal JVM necessary to run the application.

To start with, we need to have GraalVM installed and the GRAALVM_HOME environment variable configured.

We’ll now stop the application (Ctrl + C), if not stopped already, and run the command:

./mvnw package -Pnative

To o verify that our native artifact was properly constructed: Run:

./mvnw verify -Pnative

To create a Docker Container image using our native executable.

./mvnw package -Pnative -Dnative-image.docker-build=true

The project generation created a Dockerfile.native:

FROM registry.fedoraproject.org/fedora-minimal
WORKDIR /work/
COPY target/*-runner /work/application
RUN chmod 775 /work
EXPOSE 8080
CMD ["./application", "-Dquarkus.http.host=0.0.0.0"]

To create a docker image:

docker build -f src/main/docker/Dockerfile.native -t quarkus/quarkus-project .

Run the container using:

docker run -i --rm -p 8080:8080 quarkus/quarkus-project

To test our modified REST to validate our application:

$ curl localhost:8080/dessertmenu/orderspecial/Apple

Expect

You have ordered: Apple Pie with icecream or fresh cream

Method 2 create a Quarkus project using the Code With Quarkus website

Open this URL : https://code.quarkus.io/
Here you get to choose all your dependencies.
These dependencies are Quarkus Complient.
And then you download a zip file of a generated Project.

Configuring Datasources

Quarkus now expects to launch a Docker container with your database of choice you need to configure this so as to not get errors.
Please refer to our Bibliography

Bibliography

configuring_data_sources_in_your_quarkus_applications
[configuring_data_sources_in_your_quarkus_applications/assembly_intro-datasources_quarkus-configuring-datasources](https://access.redhat.com/documentation/en-us/red_hat_build_of_quarkus/1.7/html/configuring_data_sources_in_your_quarkus_applications/assembly_intro-datasources_quarkus-configuring-datasources
REACTIVE SQL CLIENTS
USING HIBERNATE ORM AND JAKARTA PERSISTENCE \