Trying to retrieve HttpSession object

Question

For some background, I'm using JBoss AS 7 with EJB. I'm sending a message to my server from the client using errai message bus when it initially connects to retrieve its session ID so that I can make requests from it later on and have the server respond to the specific client.

How do I go about doing this? Can I inject a HttpSession object server side somehow? I'm very new to this so please bear with me. If I'm too vague let me know and I'll try to elaborate more.

**Never** mix Http components with your EJB components, note that an EJB must contain business logic only and, from the MVC pattern point of view, the HttpSession is part of the Controller (since you access to it through servlets or another controller) while EJB is part of the Model. Instead of injecting the `HttpSession` in your EJB, pass the necessary values to be in your EJB as parameters instead. — Luiggi Mendoza, Jul 29 '13 at 02:40
@LuiggiMendoza I'm not sure how to do that. When the servlet starts up am I able to get the HttpSession request some how and then get the id out of there? Can I specify some methods somewhere that will allow me to do what you just mentioned? — Graham, Jul 29 '13 at 02:43
You can access to the `HttpSession` on every request by doing `HttpSession session = request.getSession(false)` and then you can use `session.getId` to get the current jsessionid associated with the `HttpSession`. Looks like it would be better if you explain your functional requirement to help you solve the real problem. — Luiggi Mendoza, Jul 29 '13 at 02:50
@LuiggiMendoza I'm using errai messaging bus for transferring messages to and from my server. When the client initially connects to the server to retrieve information I want to get its session id to use with the errai bus in order to send messages to specific clients. The main question is, where can I get this request object? How can I obtain it in my code somewhere? — Graham, Jul 29 '13 at 02:54

score 0 · Answer 1 · answered Jul 29 '13 at 03:27

// the following variable is in the Http servlet service() method arguments
// only shown here this way to demonstrate the process
javax.servlet.http.HttpServletRequest serviceRequest;
javax.servlet.http.HttpServletResponse serviceResp; // addCookie()
javax.servlet.http.HttpSession cecil;
javax.servlet.http.Cookie[] reqCk;


// "(boolean overload) "true" creates the session" or call the other overload version method with no argument 
// to retrieve the session getSession() "the server container stores and creates sessions"
// false in that version is to avoid bothering for a session to cut down uneeded processing


cecil = serviceRequest.getSession();//creates a session if it does not have one


String httpSession_ID = cecil.getID();


if((reqCk = serviceRequest.getCookies()) == null){

// perhaps create a cookie here using "new class "
// cookiePiece = new javax.servlet.http.Cookie("COOKIENAME",....); ....YOU MUST LEARN THE COOKIE PARTS WRITING RULES FOR BROWSER COOKIES !!! ; ; ;
serviceResp.addCookie(cookiePiece); // now is on the servers array "reqCk"

}else{

// process the cookie here using javax.servlet.http.Cookie methods

}

Other ways of storing and retrieving data are session scoped JSP or JSF beans.

score 0 · Accepted Answer · answered Jul 30 '13 at 15:42

If you are sending a message to an ErraiBus service method, you will have the Message object available. You can retrieve the session from it and get that session's ID like this:

@Service
public class ClientHelloService implements MessageCallback {
  @Override
  public void callback(final Message message) {
    HttpSession session = message.getResource(
        HttpServletRequest.class, HttpServletRequest.class.getName()).getSession();
    System.out.println("Client said hello. Session ID: " + session.getId());
  }
}

If you are instead sending the message to an Errai RPC endpoint, you will not have such easy access to the message. In this case, you will have to use the RpcContext.getSession() method:

@Service
public class ClientHelloRpcServiceImpl implements ClientHelloRpcService {
  @Override
  public void hello() {
    HttpSession session = RpcContext.getHttpSession();
    System.out.println("Client said hello. Session ID: " + session.getId());
  }
}

The way this works is simple but ugly: RpcContext class stores the Message object that contained the RPC request in a ThreadLocal, and it just retrieves the HttpSession from that.

Trying to retrieve HttpSession object

2 Answers2