Run the Application

Spring Boot makes it easier to run a Java web application because it handles starting and configuring the server.

To run your application, run the Application class that contains the main() method that starts Spring Boot. IntelliJ detects automatically that you have a class with a main() method and displays it in the run configurations drop-down.

To start your application, open Application.java and click the play button next to the code line containing the main() method.

After you’ve run the application once from the main() method, it will appear in the run configurations drop-down in the main toolbar (see screenshot). On subsequent runs, you can run the application from there.

The first time you start a Vaadin application, it downloads front-end dependencies and builds a JavaScript bundle. IntelliJ indexes all the added dependencies. It won’t need to do that when run subsequently.

You’ll know that your application has started when you see output in the console similar to what you see here:

Tomcat started on port(s): 8080 (http) with context path ''

The development mode in Vaadin also opens a browser window for you automatically. You’ll see a content placeholder and image similar to the screenshot here: