Java Reference
In-Depth Information
•
getId()—
Returns a string with a unique identifier representing this session
•
getPathParameters()—
Returns parameters passed in as a part of the URL
•
getQueryString()—
Returns the query string of the URL
(?vaca-
tion=yes
)
•
getRequestParameterMap()—
Query string parsed and returned in a map
•
getRequestURI()—
URI under which this session was opened
•
isOpen()—
Returns
true
if the connection is still valid
•
isSecure()—
Returns
true
if the connection is using secure sockets
•
getUserPrincipal()—
Returns the authenticated user or null if none
•
getUserProperties()—
Returns a
Map<String,String>
that can be
used to store data
•
addMessageHandler()
—registers a message handler used by programmatic
endpoints
If the user has logged into the application via realm-based security, the
getUserPrin-
cipal()
will return the principal object. This is used in the ActionBazaar example in the
next section. The
getId()
method is useful to identify a specific session; remember that
there may be multiple sessions open to one client (
getOpenSessions()
will provide
a list), so don't assume there's one session for a client or attempt to use an IP address to
identify an end user.
Validity of isOpen
With the
isOpen()
call, remember that
isOpen()
is only valid the instant it's called.
Just because it returns
true
doesn't mean the connection is still open and that your next
call to send a message will succeed. The client may be in the process of closing the con-
nection and a split millisecond later it'll actually be closed.
isOpen()
is useful only if it
returns
false
. Don't make any assumptions with
isOpen()
!
In the next section we'll look at decoders and encoders, which you'll need to understand
when processing messages.
