src/main/java/org/efaps/ui/filter/AbstractFilter.java
protected void setLoggedInUser(final HttpServletRequest _request,
                                   final String _userName)
    {
        if (_userName == null) {
            _request.getSession(true).removeAttribute(this.sessionParameterLoginName);
        } else {
            _request.getSession(true).setAttribute(this.sessionParameterLoginName,
                            _userName);
        }
    }
protected void setLoggedInUser(final HttpServletRequest _request,
                                   final String _userName)
    {
        if (_userName == null) {
            _request.getSession(true).removeAttribute(this.sessionParameterLoginName);
        } else {
            _request.getSession(true).setAttribute(this.sessionParameterLoginName,
                            _userName);
        }
    }
Stores the logged in user name in a session attribute of the http servlet
request. If the new user name is <code>null</code>, the session attribute
is removed.

@param _request http servlet request
@param _userName name of logged in user to set (or null if not defined)