org.apache.wicket.protocol.http.servlet

Class WicketSessionFilter

java.lang.Object

org.apache.wicket.protocol.http.servlet.WicketSessionFilter

All Implemented Interfaces:

javax.servlet.Filter

public class WicketSessionFilter
extends Object
implements javax.servlet.Filter

This filter can be used to make the Wicket WebSession instances available to non-wicket servlets.

The following example shows how this filter is setup to for a servlet. You can find the example in the wicket-examples project.

  <!-- The WicketSesionFilter can be used to provide thread local access to servlets/ JSPs/ etc -->
  <filter>
    <filter-name>WicketSessionFilter</filter-name>
    <filter-class>org.apache.wicket.protocol.http.servlet.WicketSessionFilter</filter-class>
    <init-param>
      <param-name>filterName</param-name>
      <!-- expose the session of the input example app -->
      <param-value>FormInputApplication</param-value>
    </init-param>
  </filter>
 
  <!-- couple the session filter to the helloworld servlet -->
  <filter-mapping>
    <filter-name>WicketSessionFilter</filter-name>
    <url-pattern>/helloworldservlet/*</url-pattern>
  </filter-mapping>
  ...
 
  <servlet>
    <servlet-name>HelloWorldServlet</servlet-name>
    <servlet-class>org.apache.wicket.examples.HelloWorldServlet</servlet-class>
  </servlet>
 
  <servlet-mapping>
    <servlet-name>HelloWorldServlet</servlet-name>
    <url-pattern>/helloworldservlet/*</url-pattern>
  </servlet-mapping>
 

Note: If both WicketFilter and WicketSessionFilter are mapped to the same url pattern, make sure to have the <filter-mapping> for WicketFilter first in your web.xml.

After that, you can get to the Wicket session in the usual fashion:

 if (Session.exists())
 {
        Session wicketSession = Session.get();
 }
 

Make sure to test for session existence first, like the HelloWorldServlet does:

 public class HelloWorldServlet extends HttpServlet
 {
        public void doGet(HttpServletRequest req, HttpServletResponse res) throws ServletException,
                IOException
        {
                res.setContentType("text/html");
                PrintWriter out = res.getWriter();
                String message = "Hi. " +
                        (Session.exists() ? " I know Wicket session " + Session.get() + "."
                                : " I can't find a Wicket session.");
                out.println(message);
                out.close();
        }
 }
 

Author:

Eelco Hillenius

Constructor Summary

Constructors

Constructor and Description
WicketSessionFilter() Construct.

Method Summary

Modifier and Type	Method and Description
void	destroy()
void	doFilter(javax.servlet.ServletRequest request, javax.servlet.ServletResponse response, javax.servlet.FilterChain chain)
void	init(javax.servlet.FilterConfig filterConfig)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

WicketSessionFilter

public WicketSessionFilter()

Construct.

Method Detail

init

public void init(javax.servlet.FilterConfig filterConfig)
          throws javax.servlet.ServletException

Specified by:

init in interface javax.servlet.Filter

Throws:

javax.servlet.ServletException

See Also:

Filter.init(javax.servlet.FilterConfig)

doFilter

public void doFilter(javax.servlet.ServletRequest request,
                     javax.servlet.ServletResponse response,
                     javax.servlet.FilterChain chain)
              throws IOException,
                     javax.servlet.ServletException

Specified by:

doFilter in interface javax.servlet.Filter

Throws:

IOException

javax.servlet.ServletException

See Also:

Filter.doFilter(javax.servlet.ServletRequest, javax.servlet.ServletResponse, javax.servlet.FilterChain)

destroy

public void destroy()

Specified by:

destroy in interface javax.servlet.Filter

See Also:

Filter.destroy()