How to use <jesi:personalize> tag for page personalization
After completing this How-To you should be able to:
Use <jesi:personalize> tag to customize your page by
substituting the cookie values before serving the cached page.
Run the sample code to do the same using the instructions
provided.
Introduction
The main purpose of
cookies is to identify users and possibly prepare customized web pages for
them. When you enter a web site using cookies, you may be asked to fill out
a form providing such information as your name and interests. This information
is packaged into a cookie and sent to your web browser which stores it for
later use. The next time you go to the same web site, your browser will send
the cookie to the Web server. The server can use this information to present
you with custom web pages. So, for example, instead of seeing just a generic
welcome page you might see a welcome page with your name on it.
Let us now move one step
ahead towards reducing processing overhead on the origin server, and enhancing
its capability and availability by caching the dynamic content using OracleAS
Web Cache. Web Cache acts as a content aware server accelerator and tries to
reduce the load on busy web servers by storing frequently accessed page in memory,
eliminating the need to repeatedly process the request for those pages on the
mid-tier servers
In the web pages, where
the dynamic content is generated using the cookie values, these pages can be
cached using the <jesi:personalize> tag. The personalize tag inserts personalized
content from the cookie in its place holder of the page. This processing is
done by the ESI processor built within the Web Cache.The first browser request
to the page is sent to the origin server. Web Cache caches this page based on
the cache policy set on the page. Succeeding requests to the pages are handled
at Web Cache itself. ESI processor substitutes the cookie values in the cached
page and the request are sent to the origin server.
Pre-requisites for running the example
You will need the following to
run this example -
Oracle Application Server (9.0.3 or above). This can be downloaded
from here
Oracle JDeveloper (9.0.3 or above). This can be downloaded from here. This
is optional and required only if you wish to deploy from JDeveloper.
Description
This sample application has two web pages viz, welcome.html
and the display.jsp. Users enter their information like title, first name
and last name in the first page, welcome.html. This page stores the user information
in the cookie and sent the request to the second page, display.jsp. This page
is a dynamic web page, which retrieves values stored in the cookie and displays
it. With out any cache server like OracleAS Web Cache, this page will be generated
for every request. Using the <jesi:personalize> tag these requests are
handled at Web Cache itself. ESI Processor retrieves the user information
stored in the cookies and substitutes them in the dynamic page cached in the
cache server. The dynamic content is requested only once and served multiple
times by the cache server. This can be visualized by the time stamp generated
in the dynamic page.
Code Snippet
Here is the code which will insert an ESI placeholder
with the cookie name and value in the response body.
.....
<tr class="tabledata">
<td>Welcome: </td>
<td align="left">
<jesi:personalize
name="title"/>
<jesi:personalize
name="firstname"/>
<jesi:personalize
name="lastname"/>
</td>
</tr>
.....
Fig1
As shown in Fig1, <jesi:personalize> tag is used to display the user name
by using the cookie variable, if the cookies( title, firstname, lastname)
are found in the request and has a non-null value, its value will be substituted
in the page. JESI tag library converts these tags into ESI tags as shown in
Fig 2.
.....
<tr class="tabledata">
<td>Welcome: </td>
<td align="left">
<ESI:VARS>$(HTTP_COOKIE{"title"}</ESI:VARS>
<ESI:VARS>$(HTTP_COOKIE{"firstname"}</ESI:VARS>
<ESI:VARS>$(HTTP_COOKIE{"lastname"}</ESI:VARS>
</td>
</tr>
......
Fig2
After this ESI processor will try to retrieve
the value of all these cookies( title, firstname, lastname) and try to replace
them by there value in ESI processor without sending the request back to
the origin server.
In our example we are
displaying time stamp also in display.jsp page and this whole page is cached
by using <jesi:control> tag for 60 seconds so if any other user enter
his name in welcome.jsp and submit before the page expiration time, he will
also see the same time stamp along with with his name and after 60 seconds the
cached page (display.jsp) gets expired and he will see different time in the
screen along with his name. This is how <jesi:personalize> tag can be
used to customize page for different users while share same cached information
among different users.
Deploying the Sample
The complete source code for this sample is available
here.
This section discusses the instructions to run
the sample application
Step 1
Unjar Personalize.jar
using Winzip, or using the following command:
> jar -xvf Personalize.jar
This creates a directory Personalize.
Step 2
If you are using JDeveloper then, follow these steps
Open Oracle JDeveloper and use File/Open option to select thePersonalize.jws from the Personalize
directory.
Next, select Project/Make Personalize.jpr from main menu.
Create an application server connection
Go to Connections -> Application Server Connection.
Right Click and click New connection..
In step 1, enter connection name and select Oracle Application
Server
In step 2, enter user name and password
In step 3, enter Enterprise Manager's host name, port
number and Remote Application Server home directory(required only if deployed
on remote machine).
In step 4, click Next and Test the connection. Click
Finish button.
Now, Right click Personalize.deploy and select Deploy to <connection
name>, to the application server connection, which you have created in
the previous step.
Step 3
To deploy the application using EM.
follow the steps.
Go to EM web site -> default oc4j home.,
Choose Deploy EAR file
Enter J2EE Application name, Click the Browse button and
choose Personalize.ear from <SAMPLE_HOME>/deploy/Personalize.ear
Enter the Application name as Personalize and click next
Enter URL mapping as /Personalize and click Finish
Click Deploy to deploy the application.
Running the Sample
Access the page on the browser, using the following url.
where, <host_name> is the machine on which OracleAS Web Cache is installed and <port>
is the port on which Web Cache listener is running.
For Example, http://incq185b.idc.oracle.com:7777/Personalize/welcome.html
Steps to run the application
Open two browser window and enter the above url in both of them.
Enter your name in first browse and submit.
Enter the name of your friend in other browser and submit ( Since
the cached page expires in 60 seconds any page request within 60 seconds
will have same timestamp).
In first browser you should see your name with time stamp.
In second browser you should see your friends name with the same
time stamp.
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