Database Reference
In-Depth Information
Object
obj
=
session
.
getAttribute
(
"count"
);
if
(
obj
==
null
)
count
=
0
;
else
count
=
Integer
.
parseInt
(
obj
.
toString
());
ArrayList
timestamp
=
(
ArrayList
)
session
.
getAttribute
(
"timestamp"
);
if
(
timestamp
==
null
)
timestamp
=
new
ArrayList
();
// increment counter, add current timestamp to timestamp array
count
=
count
+
1
;
timestamp
.
add
(
new
Date
());
if
(
count
<
10
)
// save updated values in session object
{
session
.
setAttribute
(
"count"
,
String
.
valueOf
(
count
));
session
.
setAttribute
(
"timestamp"
,
timestamp
);
}
else
// restart session after 10 requests
{
session
.
invalidate
();
}
%>
<html>
<head><title>
JSP Session Tracker
</title></head>
<body>
<p>
This session has been active for
<%=
count
%>
requests.
</p>
<p>
The requests occurred at these times:
</p>
<ol>
<%
for
(
int
i
=
0
;
i
<
timestamp
.
size
();
i
++)
out
.
println
(
"<li>"
+
timestamp
.
get
(
i
)
+
"</li>"
);
%>
</ol>
<p>
Reload page to send next request.
</p>
</body>
</html>
sess_track.jsp
is included in the
mcb
application (see
Recipe 18.3
). Invoke it from your
browser and reload it a few times to see how the display changes.
The
session.setAttribute()
method used in
sess_track.jsp
places information into
the session so that it can be found by later invocations of the script. But session attributes
also can be shared with other scripts in the same application context, which have access
to the same information. You'll see this with our next version of the script, which when
you invoke it accesses the same session information as
sess_track.jsp
.
