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我正在使用 SpringMVC 编写 Web 应用程序。我想在用户注销之前保留一些数据。早些时候我是这样做的@SessionAttributes("someData")，但后来我不得不@ModelAttribute("someData") someDataType someData为每个请求映射方法输入参数。所以这就是我所做的：

我的 AccessData 类：

@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;
    }
}

第一个控制器（这里我从表单获取并验证用户输入）：

@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);
    }
}

第二个控制器：

@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);
    }
}

问题是当我在第二个控制器中打印 userKey 值时，该值为空。我检查了我是否从服务器中获取了正确的数据，LoginController没关系。那么我做错了什么？提前感谢您的帮助

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1 回答 1

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问题是您正在为 accessData 变量分配一个新对象。相反，您应该更新它已经引用的对象的字段。

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);

也不需要使控制器会话范围，添加proxyMode=TARGET_CLASS到AccessData类的范围注释。

于 2012-12-07T08:12:10.510 回答