Httpsession management in springMVC

问题:

I am new to spring MVC and started to make a sample application by doing what I learned. I am planning to implement Session management in spring MVC. I found this one helpful.

But I am not able to get it clearly. We add values to the session like

HttpSession session = request.getSession(false);
session.setAttribute("key", value);
session.setAttribute("key1",  value1);

and later on we fetch values based on the keys like

session.getAttrubute("key");

but in spring MVC, I could not see anything similar and it totally confuses me.

@Controller
@SessionAttributes("thought")
public class SingleFieldController {

    @RequestMapping(value="/single-field")
    public ModelAndView singleFieldPage() {
        return new ModelAndView("single-field-page");
    }

    @RequestMapping(value="/remember")  
    public ModelAndView rememberThought(@RequestParam String thoughtParam) {
        ModelAndView modelAndView = new ModelAndView();
        modelAndView.addObject("thought", thoughtParam);
        modelAndView.setViewName("single-field-page");
        return modelAndView;
    }

}

In the above code @SessionAttributes("thought") is totally confusing me like what is this thought defined also I have no need to return a ModelAndView since I am using backbone.marionette.js

So how can I set values in a session and use them whenever required? I also have to convert the session object to my user defined object since, while returning the values to screen, I return only a List of UserDefined objects which are available in the session.

So please help me to understand it better. Maybe I am confused with the way I used jsp / servlet.

UPDATE

Below is the controller I have and provided comments

package com.hexgen.puppet;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.SessionAttributes;

import com.hexgen.puppet.CreatePuppet;

import java.util.ArrayList;
import java.util.List;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;

@Controller
public class PuppetService {

    @RequestMapping(method = RequestMethod.POST, value = "/create")
    public @ResponseBody
    void createOrder(@RequestBody CreatePuppet request) {
        //logic to add/update values in session
    }

    @RequestMapping(method = RequestMethod.GET, value = "/list")
    public @ResponseBody
    List<Puppet> getGroups() {
        //logic to retrive objects from session and convert it as List and send it back

        return puppets;
    }


}

and convert the object if needed and go on

回答1:

@SessionAttributes doesn't fully replaces the traditional HttpServlet session management. Use it if two or more Controller methods need to communicate some data. But, using this we can only achieve communication within single controller class. You do not use to read and write from and to the session explicitly if you are using @SessionAttributes. Usage of @SessionAttributes is suggested only for short lived communications. If you need to store long term data in session, it is suggested to use session.setAttribute and session.getAttribute explicitly, instead of @SessionAttributes. For more information check this out.

回答2:

You can handle session management in springmvc like this. here is a controller method

@RequestMapping(value = { "/login" }, method = RequestMethod.POST)
@ResponseBody
public String login(HttpSession session,String username,String password) throws Exception {
    Member member=userService.authenticateUser(username, password);
    if(member!=null) {
        session.setAttribute("MEMBER", member);
    } else {
        throw new Exception("Invalid username or password");
    }
    return Utils.toJson("SUCCESS");
}

user will be passing username and password while Spring will automatically inject session attribute. we will authenticate this username and password from db. For this we will be using some service method which will in turn call some method of repository to get the Object of Member class and return it here in the controller. Whereever in your application method you need the information kept in the session pass it in the argument to the handler. You can find more details how this information can be verified at every method call at http://faisalbhagat.blogspot.com/2014/09/session-management-with-spring-mvc.html