This manual is a work in progress and is currently incomplete.

3 Launching

This chapter introduces how to launch a Ratpack application, and the associated launch time configuration.

3.1 Launch configuration

To launch a Ratpack application, you must create a LaunchConfig. This can then be used with the RatpackServerBuilder method to create a RatpackServer that can then be started.

Note that one of the LaunchConfig object’s responsibilities is to provide a HandlerFactory implementation. This factory is responsible for creating the handler that is effectively the Ratpack application. See the chapter on handlers for more details.

One option for building a LaunchConfig is to use the LaunchConfigBuilder. Another option is to use the LaunchConfigFactory which is able to build a launch config from system properties and a properties file.

3.2 Main classes

Ratpack also provides some ready to use “main” classes that can be used to start the application. These main classes build on top of LaunchConfigFactory.

The RatpackMain is a bare bones entry point and is suitable for use in most cases.

The GroovyRatpackMain entry point configures a Groovy based application to be launched.