SomeController.java

@Controller
@Path("/somepage")
public class SomeController {

  @Inject
  private Result result;

  @Inject
  private Validator validation;

  @Get
  public void renderPage() {
    result.include("foo", "Something to include on the page");
    result.include("bar", "More stuff to include on the page");
  }

  @Post
  public void processForm(@NotNull @Valid Form form) {

    validation.onErrorForwardTo(this).renderPage();

    // validation has passed, perform business logic here

  }

}