Here's for 7.x:
public class MyUI extends UI {
@WebServlet(value = "/*", asyncSupported = true, initParams = {
@WebInitParam(name = "ui", value = "com.example.MyUI"),
@WebInitParam(name = "productionMode", value = "false") })
public static class Servlet extends VaadinServlet {
}
@Override
protected void init(VaadinRequest request) {
..
}
}
And for 7.1 and newer:
public class MyUI extends UI {
@WebServlet(value = "/*", asyncSupported = true)
@VaadinServletConfiguration(productionMode = false, ui = MyUI.class)
public static class Servlet extends VaadinServlet {
}
@Override
protected void init(VaadinRequest request) {
..
}
}