在控制器中声明 HttpSession 对象 [英] Declaring HttpSession Object in Controller

问题描述

我们已经定义了一个控制器，需要声明HttpSession对象.我可以自动装配它或作为对象传递给方法.这两个选项有什么区别，哪个更可取?

We have defined a controller and need to declare the HttpSession object. I can autowire it or pass as an object to the method. What is the difference between the two options and which is preferable?

选项 1

@Controller
public class UserController {

    @Autowired
    HttpSession session;
    ..
    ..
}

选项 2

@Controller
public class UserController {

    @RequestMapping(value="/user", method=RequestMethod.GET)
    public @ResponseBody User getUser(HttpSession session) {
    ..
    ..
    }
}

推荐答案

在控制器中，您应该使用 Option2.

In a Controller, you should use Option2.

会话从 http 请求开始，结束直到请求停止，但控制器在应用程序停止之前可用.所以你不应该在 Controller 中自动装配 HttpSession.

A session is start from a http request begin, end until the request stop, but the controller is available until the application stoped. So you should not autowired the HttpSession in Controller.

您可以像这样自动连接 http 会话的一种情况:

One of the situation you can autowired the http session like that:

@Component
@Scope(value=WebApplicationContext.SCOPE_SESSION)
public class CurrentUserHolder{

    @Autowired
    private HttpSession session;

    public User currentUser() {
        return this.get();
    }

    @Override
    public  User get() {
        return (User)session.getAttribute("currentUser");
    }
}

因此您可以在无法获取会话的服务中获取当前用户:

So you can get current user in a service which can not get the session:

@Service
public class UserService{
    private @Autowired CurrentUserHolder currentUserHolder;
    ......
}

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