Kotlin version of the Spring PetClinic Sample Application

This is a Kotlin version of the spring-petclinic Application.

Technologies used

• Language: Kotlin
• Core framework: Spring Boot 3 with Spring Framework 6 Kotlin support
• Server: Apache Tomcat
• Web framework: Spring MVC
• Templates: Thymeleaf and Bootstrap 5
• Persistence : Spring Data JPA
• Databases: H2 and MySQL both supported
• Build: Gradle Script with the Kotlin DSL
• Testing: Junit 5, Mockito and AssertJ

Running petclinic locally

With gradle command line

git clone https://github.com/spring-petclinic/spring-petclinic-kotlin.git
cd spring-petclinic-kotlin
./gradlew bootRun

With Docker

docker run -p 8080:8080 springcommunity/spring-petclinic-kotlin

You can then access petclinic here: http://localhost:8080/

Database configuration

In its default configuration, Petclinic uses an in-memory database (H2) which gets populated at startup with data. The h2 console is automatically exposed at http://localhost:8080/h2-console and it is possible to inspect the content of the database using the jdbc:h2:mem:{uuid} url (the uuid param could be find in the startup logs).

A similar setup is provided for MySql in case a persistent database configuration is needed. Note that whenever the database type is changed, the data-access.properties file needs to be updated and the mysql-connector-java artifact from the pom.xml needs to be uncommented.

You could start a MySql database with docker:

docker run -e MYSQL_USER=petclinic -e MYSQL_PASSWORD=petclinic -e MYSQL_ROOT_PASSWORD=root -e MYSQL_DATABASE=petclinic -p 3306:3306 mysql:5.7.8

Further documentation is provided here.

Looking for something in particular?

Features	Class, files or Java property files
The Main Class	PetClinicApplication
Properties configuration file	application.properties
Gradle build script with Kotlin DSL	build.gradle.kts
Caching Configuration	CacheConfig

Import and run the project in IntelliJ IDEA

• Make sure you have at least IntelliJ IDEA 2017.2 and IDEA Kotlin plugin 1.1.60+ (menu Tools -> Kotlin -> configure Kotlin Plugin Updates -> make sure "Stable" channel is selected -> check for updates now -> restart IDE after the update)
• Import it in IDEA as a Gradle project
  • Go to the menu "File -> New -> Project from Existing Sources... "
  • Select the spring-petclinic-kotlin directory then choose "Import the project from Gradle"
  • Select the "Use gradle wrapper task configuration" radio button
• In IntelliJ IDEA, right click on PetClinicApplication.kt then "Run..." or "Debug..."
• Open http://localhost:8080/ in your browser

Documentation

• Migrez une application Java Spring Boot vers kotlin (french)
• Migration Spring Web MVC vers Spring WebFlux (french)

Publishing a Docker image

This application uses Google Jib to build an optimized Docker image into the Docker Hub repository. The build.gradle.kts has been configured to publish the image with a the springcommunity/spring-petclinic-kotlin image name.

Build and push the container image of Petclinic to the Docker Hub registry:

gradle jib -Djib.to.auth.username=<username> -Djib.to.auth.password=<password>

Interesting Spring Petclinic forks

The Spring Petclinic master branch in the main spring-projects GitHub org is the "canonical" implementation, currently based on Spring Boot and Thymeleaf.

This [spring-petclinic-kotlin][] project is one of the several forks hosted in a special GitHub org: spring-petclinic. If you have a special interest in a different technology stack that could be used to implement the Pet Clinic then please join the community there.

Interaction with other open source projects

One of the best parts about working on the Spring Petclinic application is that we have the opportunity to work in direct contact with many Open Source projects. We found some bugs/suggested improvements on various topics such as Spring, Spring Data, Bean Validation and even Eclipse! In many cases, they've been fixed/implemented in just a few days. Here is a list of them:

Name	Issue
Spring JDBC: simplify usage of NamedParameterJdbcTemplate	SPR-10256 and SPR-10257
Bean Validation / Hibernate Validator: simplify Maven dependencies and backward compatibility	HV-790 and HV-792
Spring Data: provide more flexibility when working with JPQL queries	DATAJPA-292

Contributing

The issue tracker is the preferred channel for bug reports, features requests and submitting pull requests.

For pull requests, editor preferences are available in the editor config for easy use in common text editors. Read more and download plugins at http://editorconfig.org.