Marek Lewandowski
Marek Lewandowski

Reputation: 109

Spring MVC passing data between controllers

I'm writing web application using SpringMVC. I would like to keep some data in session until user logout. Earlier I did it by @SessionAttributes("someData"), but then I had to put @ModelAttribute("someData") someDataType someData as argument for every request mapping method. So this is what I did :

My AccessData class :

@Component
@Scope(value = "session")
public class AccessData {

    private long userID;

    private String userKey;

    public AccessData(long ID, String key) {
        this.userID = ID;
        this.userKey = key;
    }

    public long getUserID() {
        return userID;
    }

    public void setUserID(long userID) {
        this.userID = userID;
    }

    public String getUserKey() {
        return userKey;
    }

    public void setUserKey(String userKey) {
        this.userKey = userKey;
    }
}

First controller(here I'm getting and validating user input from form) :

@Controller
@Scope(value = "session")
public class LoginController {

    @ModelAttribute("accessData")
    public AccessData getAccessData() {
        return this.accessData;
    }

    private Utils utilsService;

    private LoginService loginService;

    @Autowired
    private AccessData accessData;

    @Autowired
    public LoginController(LoginService loginService, Utils utils) {
        this.loginService = loginService;
        this.utilsService = utils;
    }

    @RequestMapping(value = ControllerPaths.LOGIN, method = RequestMethod.POST)
    public ModelAndView showLoginStatus(
            @ModelAttribute(LOGINDATA) LoginData loginData) {
        try {
            accessData = loginService.validateLoginData(loginData);
        } catch (IncorrectLoginDataException e) {
            logger.trace("Showing fail login screen...");
            return utilsService.getShowView(ViewPaths.LOGIN_FAIL);
        } catch (HTTPException e) {
            return utilsService.getShowViewWithStringAttribute(
                    ViewPaths.INFO_VIEW, MESSAGE, CONNECTION_ERROR);
        }
        return utilsService.getShowView(ViewPaths.LOGIN_SUCCESS);
    }
}

Second controller :

@Controller
@Scope(value = "session")
public class SecondController {

    @ModelAttribute("accessData")
    public AccessData getAccessData() {
        return this.accessData;
    }

    private Utils utilsService;

    private LoginService loginService;

    @Autowired
    private AccessData accessData;

    @Autowired
    public SecondController(LoginService loginService, Utils utils) {
        this.loginService = loginService;
        this.utilsService = utils;
    }

    @RequestMapping(value = ControllerPaths.SHOW_ACCESS_DATA, method =   RequestMethod.GET)
    public ModelAndView showAccessData(
        System.out.println(accessData.getUserKey());
        return utilsService.getShowView(ViewPaths.INDEX);
    }
}

The problem is that when I'm printing userKey value in second controller, the value is null. I checked if I'm getting correct data from server in LoginController and it's ok. So what am I doing wrong? Thanks in advance for help

Upvotes: 4

Views: 7183

Answers (1)

gkamal
gkamal

Reputation: 21000

The problem is that you are assigning a new object to the accessData variable. Instead you should update the field of the object that it is already referring to.

accessData = loginService.validateLoginData(loginData);

// Replace above line with something like this. Implement the copyProperties
// method to copy the attributes you need
AccessData newAccessData = loginService.validateLoginData(loginData);
copyPropteries(accessData,newAccessData);

Also it is not required to make the Controllers session scoped, add proxyMode=TARGET_CLASS to the scope annotation of the AccessData class.

Upvotes: 2

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