控制器库直接访问HttpServletRequest

Question

I have numerous controllers in my application that extend a central controller class. Currently, in every controller function, I have to pass the request into this function in order for my function to grab the current username. Is it possible for this controller class to get the request on it's own without requiring it as an extra parameter?

public class Controller {
    protected String environment;

    public Controller () {

    }

    public ModelAndView prepareModel (HttpServletRequest request, ModelAndView model) {
        contentDao.clearExpiredLocks();

        model.addObject("currentUser", contentDao.findUser(request.getRemoteUser()));

        //define current environment
        this.environment = (request.getRequestURL().indexOf("localhost") > 0) ? "dev" : "uat";
        model.addObject("environment", this.environment);

Answer 1

You can use something like this:

public abstract class AbstractController {

    protected HttpServletRequest req

    protected AbstractController(HttpServletRequest req) {
        this.req  = req
    }
}

public class ConcreteController extends AbstractController {

    protected ConcreteController(String name) {
        super(name);
    }

    private void getUserName(){
        this.req.getRemoteUser();
    }    
}

That's just one quick tip, I believe that there are more possibilities how to do that.

Answer 2

You can get the current HttpServletRequest as follows:

HttpServletRequest request = (HttpServletRequest) RequestContextHolder
    .currentRequestAttributes()
    .resolveReference(RequestAttributes.REFERENCE_REQUEST); 

You can use this code in a method of your controller, or use it to expose request as a request-scoped bean and inject the corresponding scoped proxy as a field of your controller.

Answer 3

In my case, What I did is : I get user MainController.getLoginPerson() and use all user's info in all controllers. All controllers extends to MainController. Here is method MainController.getLoginPerson():

MainController.getLoginPerson() {
    // calls to authentication service method
    authenticationService.getLoginPerson();
}

authenticationService.getLoginPerson() {
            Authentication auth = SecurityContextHolder.getContext().getAuthentication();
        if (auth != null) {
            return (UserPrincipalImpl) auth.getPrincipal();
        } else {
            return null;
        }
}