How do you wrap validation for a function within another function?

Say, for example, you have a bunch of functions that all need to check for login validation. To begin with, it looks something like:

public Response createThing(){
   if(!validLogin(httpRequest, uriInfo)){
      logInvalidLogin();
      return Response.status(Response.Status.FORBIDDEN);
   }

   //Do the function
}

That first block of code exists at the top of every service call, but I don't know how to wrap it into another function because it contains a return statement. I would like something similar to the following:

public Response createThing(){
   validateLogin(httpRequest, uriInfo);

   //Do the function
}

or

public Response createThing(){
   //Implied check somehow?

   //Do the function
}

I'm sure there's some pattern or convention out there that people use. Thanks.