Java HttpSession .getAttribute(String name)

Question

I have a simple, short question but not found the answer anywhere. I created an HttpSession and want to get an attribute from it, for example a User object.

HttpSession session = request.getSession(true);
Object userObject = session.getAttribute("name");
if ((userObject != null) && (userObject instanceof User)) {
    User currentUser = (User) userObject;
    ...
}

The question is the following: .getAttribute function gets a String name as parameter - what is the name? From where do I know the name? Is it predefined somewhere? - then where to define another one?

Thank you!

score 9 · Accepted Answer · answered Jul 28 '16 at 20:48

9

Usually, you add attributes to the session yourself like so:

User someObject = new User();
session.setAttribute("pickaName", someObject);

Then you can get the session and pull off this attribute using that same name you used earlier like so:

User sameObject = (User) session.getAttribute("pickaName");

answered Jul 28 '16 at 20:48

LeHill

449
7
13

Thank you, I think I got it. If I'm right, if I want to get for example a User object with getAttribute in a session, I have to create for example a login method, where I set the attribute for the user, am I? – Display Name Jul 28 '16 at 21:07
Exactly. Create the object and add it first, then you can retrieve it later. – LeHill Jul 28 '16 at 21:12
Thank you, it helped me a lot! – Display Name Jul 28 '16 at 21:25

score 0 · Answer 2 · answered Jul 28 '16 at 21:00

.getAttribute function gets a String name as parameter - what is the name?

If you want to get attributes from Session, you need to set them to the Session before like so:

User aux = new User();
HttpSession session = new HttpSession();
session.setAttribute("myUserObject", aux);
User user = (User) session.getAttribute("myUserObject");

Java HttpSession .getAttribute(String name)

2 Answers2