Spring Boot GWT

This is a demo project to show Spring Boot in conjunction with GWT. It uses the latest dependencies (Spring Boot 2.0.1 and GWT 2.8.2) and Java 8. The deployed app can be found here.

Run

To run this project you have to start Spring Boot and GWT separate. If you use IntelliJ, see the IDEA Settings readme for the correct configuration.

Spring Boot can also be started with gradle.

gradlew bootRun

Test

Currently only the server side code is tested. To run the tests use the following command

gradlew test

We use Spock as testing framework because of the great readability, syntax and built in features.

Outdated dependencies

To check for outdated dependencies

gradlew dependencyUpdates -Drevision=release

Build

The project con be build to a single jar file with an embedded tomcat:

gradlew clean build

After gradle build the project the finished jar file is in build/libs/spring-boot-gwt-1.0.0.jar and can simply be started with

java -jar build/libs/spring-boot-gwt-1.0.0.jar

Heroku

To deploy this app to heroku use the Deploy to Heroku Button on the top.

Heroku uses the gradle stage task to build the project. Because Spring Boot puts everything we need into the jar file we only have to tell heroku to execute this jar file.

Technical Details

Architecture

The client side and server side are strictly separated. The GWT files are in the client package (except the .gwt.xml) and the server side code is in the server package. All static client code like the index.html and css files are inside the static folder. Gradle will also put the compiled sources in this folder.

The communication is made via JSON for which reason we have make 2 implementations of the object we send (POJO in the frontend and POJO with javax annotations in the backend).