Awesome
This is a sample application that demonstrates how to build a Kotlin + Spring Boot applications with a PostgreSQL database. The code is very concise, and the generated application is a 18 MBytes self-contained executable jar with low memory consumption.
A detailed blog post describing this application is available here.
It is used as a playground to demonstrate various features:
- Gradle build.gradle.kts file written in Kotlin instead of Groovy, see gradle-script-kotlin for more details.
- Simple User and Message domain model classes thanks to Kotlin data classes.
- The Application class shows how to configure a Kotlin Spring Boot application.
- Typesafe SQL DSL with Exposed that allows to define your SQL tables and describe your SQL requests with a fluent API without requiring code generation.
- Controllers
demonstrates how to use Spring Framework 4.3 upcoming
@GetMapping
and@PostMapping
annotation shortcuts, as well as Server-Sent Events to push data to the client. - Kotlin extensions allows to add Geospatial support to Exposed and use it as if this was supported out of the box.
- The REST API is fully tested and documented thanks to the awesome Spring REST docs , see MessageControllerTests and index.adoc.
- The client side is originally a pure HTML + Javascript application developed with OpenLayers mapping library, see index.html and map.js. But an experimental (work in progress) Kotlin2js version has ben contributed by @bashor, you can find it here.
A Spring Data version based on spring-data-jdbc-repository is also available in this branch. There is no Spring Data JPA version yet but feel free to fork this repo and contribute it with a pull request!
Run the application
-
Install a PostgreSQL database with PostGis extension, on Mac you can use Postgresapp.
-
Clone this repository.
-
Customize database configuration on application.yml.
-
Run it within your IDE or with
./gradlew bootRun
. -
Open
http://localhost:8080/
in your browser. -
Documentation should be available at
http://localhost:8080/docs/index.html
when run from the JAR.
Improvements I have in mind
- Exposed issue #24: see if Exposed could support natively data classes + repository patten.
- Spring HATEOAS issue #401: add HATEOAS support, but without having to extend
ResourceSupport
or wrapping it into aResource<Foo>
container .