The GWT-Maven 1.x plugin is used to develop, build and package GWT applications.
GWT-Maven can invoke GWTShell and GWTCompiler, merge application deployment resources (web.xml, context.xml, java dependencies) with the GWT Hosted Mode development server instance, generate GWT IsSerializable model beans from existing beans, and can also easily create deployable WAR files for GWT applications (with the correct GWT RPC service servlet entries automatically injected based on the GWT module file).
See the "Sample Example that is Quite Ample" for a complete walk through (including DataSources)