Buat REST APIs sedarhana di Quarkus

Pastikan sudah ada ada koneksi ke db dengan contoh sederhana disini: https://undebugable.blogspot.com/2025/07/setup-postgresql-dan-quarkus-dengan.html.

Berikut contoh sederhana namun powerful untuk Quarkus REST API CRUD pada entitas User. Contoh ini menggunakan resource, DTO, dan service layer agar mudah dikembangkan ke depannya.

Penjelasan singkat:

• UserResource: REST endpoint untuk CRUD.
• UserService: Logika bisnis CRUD.
• UserDTO: Data transfer object untuk input/output.
• Gunakan dependency injection dan response yang sesuai. 

build.gradle

dependencies {

... 

implementation 'io.quarkus:quarkus-rest-jackson'

... 
}

User.java

package com.yoesoff.plate.entity;

import io.quarkus.hibernate.orm.panache.PanacheEntity;
import jakarta.persistence.Entity;
import jakarta.persistence.Table;

@Entity
@Table(name = "app_users")
public class User extends PanacheEntity {
    public String username;
    public String password;
    public String email;

    // Default constructor
    public User() {
    }

    // Constructor with parameters
    public User(String username, String password, String email) {
        this.username = username;
        this.password = password;
        this.email = email;
    }

    // Getters and setters can be added if needed
}

UserDTO.java

package com.yoesoff.plate.dto;

public class UserDTO {
    public Long id;
    public String username;
    public String email;
}

 UserService.java

package com.yoesoff.plate.service;

import com.yoesoff.plate.entity.User;
import com.yoesoff.plate.dto.UserDTO;
import jakarta.enterprise.context.ApplicationScoped;
import jakarta.transaction.Transactional;
import java.util.List;
import java.util.stream.Collectors;

@ApplicationScoped
public class UserService {

    public List<UserDTO> listAll() {
        return User.listAll().stream()
                .map(entity -> toDTO((User) entity))
                .collect(Collectors.toList());
    }

    public UserDTO findById(Long id) {
        User user = User.findById(id);
        return user != null ? toDTO(user) : null;
    }

    @Transactional
    public UserDTO create(UserDTO dto) {
        User user = new User(dto.username, "default", dto.email);
        user.persist();
        return toDTO(user);
    }

    @Transactional
    public UserDTO update(Long id, UserDTO dto) {
        User user = User.findById(id);
        if (user == null) return null;
        user.username = dto.username;
        user.email = dto.email;
        return toDTO(user);
    }

    @Transactional
    public boolean delete(Long id) {
        return User.deleteById(id);
    }

    private UserDTO toDTO(User user) {
        UserDTO dto = new UserDTO();
        dto.id = user.id;
        dto.username = user.username;
        dto.email = user.email;
        return dto;
    }
}

UserResource.java

package com.yoesoff.plate.resource;

import com.yoesoff.plate.dto.UserDTO;
import com.yoesoff.plate.service.UserService;
import jakarta.inject.Inject;
import jakarta.ws.rs.*;
import jakarta.ws.rs.core.MediaType;
import jakarta.ws.rs.core.Response;
import java.util.List;

@Path("/users")
@Produces(MediaType.APPLICATION_JSON)
@Consumes(MediaType.APPLICATION_JSON)
public class UserResource {

    @Inject
    UserService userService;

    @GET
    public List<UserDTO> list() {
        return userService.listAll();
    }

    @GET
    @Path("/{id}")
    public Response get(@PathParam("id") Long id) {
        UserDTO user = userService.findById(id);
        if (user == null) return Response.status(Response.Status.NOT_FOUND).build();
        return Response.ok(user).build();
    }

    @POST
    public Response create(UserDTO dto) {
        UserDTO created = userService.create(dto);
        return Response.status(Response.Status.CREATED).entity(created).build();
    }

    @PUT
    @Path("/{id}")
    public Response update(@PathParam("id") Long id, UserDTO dto) {
        UserDTO updated = userService.update(id, dto);
        if (updated == null) return Response.status(Response.Status.NOT_FOUND).build();
        return Response.ok(updated).build();
    }

    @DELETE
    @Path("/{id}")
    public Response delete(@PathParam("id") Long id) {
        boolean deleted = userService.delete(id);
        if (!deleted) return Response.status(Response.Status.NOT_FOUND).build();
        return Response.noContent().build();
    }
} 

Postman

curl --location 'http://localhost:8080/users' \
--header 'Content-Type: application/json' \
--data-raw '{
    "username": "testuser",
    "email": "testuser@example.com"
}'