Sample URL rewrite servlet
This appendix describes how to set up an example to test session management using URL rewrites. The class SessionSampleURLRewrite has been provided since none of the standard samples use URL rewriting to manage sessions. This is because using URL rewrites requires additions to the normal servlet code.
public class SessionSampleURLRewrite extends HttpServlet
{
public void doGet (HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
{
// Step 1: Get the Session object
boolean create = true;
HttpSession session = request.getSession(create);
// Step 2: Get the session data value
Integer ival = (Integer)
session.getAttribute ("sessiontest.counter");
if (ival == null)
ival = new Integer (1);
else
ival = new Integer (ival.intValue () + 1);
session.setAttribute ("sessiontest.counter", ival);
// Step 3: Rewrite the session ID onto the URL
String contextPath = request.getContextPath();
String servletName = request.getServletPath();
String encodeString = contextPath + servletName;
String encodedURL = response.encodeURL(encodeString);
// Step 4: Output the page
response.setContentType("text/html");
PrintWriter out = response.getWriter();
out.println("<html>");
out.println("<head><title>Session Tracking Test</title></head>");
out.println("<body>");
out.println("<h1>Session Tracking Test</h1>");
out.println ("You have hit this page " + ival + " times" + "<br>");
if (!session.isNew())
{
out.println("<p>");
if(request.isRequestedSessionIdFromURL())
out.print("Your requested session ID was found in a rewritten URL");
else
out.print("Your requested session ID was NOT found in a rewritten URL");
}
// Use the rewritten URL as the link, You must enable URL Rewriting in the session Manager and
// disable cookies in either the Session Manager or the browser
out.print("<p>");
out.print("<a href=\"");
out.print(encodedURL);
out.println("\">Request this servlet again using the rewritten URL</a>");
out.println("</body></html>");
}
}
Steps to install SessionSampleURLRewrite servlet
We provide two alternatives to install the SessionSampleURLRewrite servlet:| Installing the urltest Web module |
| Adding the servlet to an installed application |
Installing the urltest Web module
Please refer to 7.6.2, Install BeenThere on detailed instructions about how to install an enterprise application. In summary, these are the steps to install urltest.war:
Adding the servlet to an installed application
Note: While convenient in a development environment, the following technique is not recommended in a production environment. |
Follow these steps to install the servlet into the sample application. This procedure can be performed whether the appserver is running or not. If the application server is running, then the changes will be picked up automatically, subject to the auto-reload settings on your Web container. If auto-reload is disabled, the servlet will not be available until the application server is restarted.
This procedure should be repeated for each of the cluster members of the cluster you are using to test session management.
<WAS_HOME>/installedApps/<node_name>/DefaultApplication.ear/Default WebApplication.war/WEB_INF/classes
For example:
c:\websphere\appserver\installedApps\app1\DefaultApplication.ear\Default
WebApplication.war\WEB_INF\classes
<WAS_HOME>/config/cells/<node_name>/applications/DefaultApplication.
ear/deployments/DefaultApplication/DefaultWebApplication.war/WEB-INF
Make sure that the IDs used follow the pattern in the file; for example the last servlet definition should be Servlet_3, so use Servlet_4 for your new servlet definition.
Example: B-2 Lines to add to web.xml file
<servlet id="Servlet_4">
<servlet-name>urltest</servlet-name>
<description>Test URL rewrite</description>
<servlet-class>SessionSampleURLRewrite</servlet-class>
</servlet>
<servlet-mapping id="ServletMapping_4">
<servlet-name>urltest</servlet-name>
<url-pattern>/servlet/urltest</url-pattern>
</servlet-mapping>
<Uri Name="/servlet/urltest"/>
Repeat these steps for each of the nodes in your server group. Once this is complete, you will be able to run the test shown in URL rewriting.
Locating the Web material
The Web material associated with this redbook is available in softcopy on the Internet from the IBM Redbooks Web server. Point your Web browser to:ftp://www.redbooks.ibm.com/redbooks/SG246198
Alternatively, you can go to the IBM Redbooks Web site at:
ibm.com/redbooks
Select the Additional materials and open the directory that corresponds with the redbook form number, SG24-6198-01.
Using the Web material
The additional Web material that accompanies this redbook includes the following files:| File name | >Description |
| urltest.war | URL Rewrite Example Web module |
| morton0206.zip | BeenThere application code |
| TradeRedirector.zip | Trade3 back-end application for WebSphere MQ scenario |
System requirements for downloading the Web material
The following system configuration is recommended:
| Hard disk space: | 10 MB |
| Operating System: | Windows, AIX, Solaris, Linux, OS/400® |
| Processor: | 500 MHz Pentium®, RS/6000®, iSeries, Sparc |
| Memory: | 384 MB RAM minimum |
How to use the Web material
| TradeRedirector.ear |
| Instructions for setup of TradeRedirector.txt |
Follow the install instructions from the text file.
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IBM is a trademark of the IBM Corporation in the United States, other countries, or both.