ServletRequest.setAttribute question

[Joerg Gippert]

Hi everyone!

I have an action servlet, that takes an attribute out of the request,
changes it and puts it back into the request. Now I´m wonderring, if I have
to remove the old attribute first, using removeAttribute() or if the API
simply overwrites any existing attribute if the same name is used.

E.g
Myobject o = (Myobject)request.getSession().getAttribute("MYATTRIBUTE")
o.changevlaue = "bla";
request.getSession().setAttribute("MYATTRIBUTE");

or do I have to do a request.getSession().removeAttribute("MYATTRIBUTE")
before I set the new one?

Thanks for any hint!

Regards,
Joerg

 

[Wendy S]

I have an action servlet, that takes an attribute out of the request,
changes it and puts it back into the request. Now I´m wonderring, if I have
to remove the old attribute first, using removeAttribute() or if the API
simply overwrites any existing attribute if the same name is used.

You don't have to remove first. It's most likely a Map of some kind holding
the request attributes, so a 'put' using an existing key will replace the
old reference with the new one.

 

[Joerg Gippert]

You don't have to remove first. It's most likely a Map of some kind holding
the request attributes, so a 'put' using an existing key will replace the
old reference with the new one.

Thanks for your reply. Should have tried it out myselfe before I post here.
It´s late here already
Yes, a Map came across my mind as well. Just was a bit confused about the
wording in the API (getAttribute) where it says"Returns the value of the
named attribute as an Object" and I was afraid, that maybe two objects of
the same name (old and new one) exist somewhere after I put it back into the
session.

Thanks again for the quick answer!

Regards,
Joerg