/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.wicket.protocol.http.servlet;
import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;
import org.apache.wicket.Application;
import org.apache.wicket.Session;
import org.apache.wicket.protocol.http.WebApplication;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* <p>
* This filter can be used to make the Wicket {@link org.apache.wicket.protocol.http.WebSession}
* instances available to non-wicket servlets.
* </p>
* <p>
* The following example shows how this filter is setup to for a servlet. You can find the example
* in the wicket-examples project.
*
* <pre>
* <!-- 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>
* </pre>
*
* After that, you can get to the Wicket session in the usual fashion:
*
* <pre>
* Session wicketSession = Session.get();
* </pre>
*
* like the HelloWorldServlet does:
*
* <pre>
* 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();
* }
* }
* </pre>
*
* </p>
*
* @author Eelco Hillenius
*/
public class WicketSessionFilter implements Filter
{
/** log. */
private static final Logger log = LoggerFactory.getLogger(WicketSessionFilter.class);
/** the filter name/ application key. */
private String filterName;
/** the session key where the Wicket session should be stored. */
private String sessionKey;
/**
* Construct.
*/
public WicketSessionFilter()
{
}
/**
* @see javax.servlet.Filter#init(javax.servlet.FilterConfig)
*/
public void init(FilterConfig filterConfig) throws ServletException
{
filterName = filterConfig.getInitParameter("filterName");
if (filterName == null)
{
throw new ServletException(
"you must provide init parameter 'filterName if you want to use " +
getClass().getName());
}
log.debug("filterName/ application key set to {}", filterName);
}
/**
* @see javax.servlet.Filter#doFilter(javax.servlet.ServletRequest,
* javax.servlet.ServletResponse, javax.servlet.FilterChain)
*/
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
throws IOException, ServletException
{
HttpServletRequest httpServletRequest = ((HttpServletRequest)request);
HttpSession httpSession = httpServletRequest.getSession(false);
if (httpSession != null)
{
if (sessionKey == null)
{
WebApplication application = (WebApplication)Application.get(filterName);
sessionKey = application.getSessionAttributePrefix(null, filterName) +
Session.SESSION_ATTRIBUTE_NAME;
log.debug("will use {} as the session key to get the Wicket session", sessionKey);
}
Session session = (Session)httpSession.getAttribute(sessionKey);
if (session != null)
{
// set the session's threadlocal
Session.set(session);
if (log.isDebugEnabled())
{
log.debug("session " + session + " set as current for " +
httpServletRequest.getContextPath() + "," +
httpServletRequest.getServerName());
}
}
else
{
if (log.isDebugEnabled())
{
log.debug("could not set Wicket session: key " + sessionKey +
" not found in http session for " + httpServletRequest.getContextPath() +
"," + httpServletRequest.getServerName());
}
}
}
else
{
log.debug("could not set Wicket session: no http session was created yet for {},{}",
httpServletRequest.getContextPath(), httpServletRequest.getServerName());
}
try
{
// go on with processing
chain.doFilter(request, response);
}
finally
{
Session.unset();
}
}
/**
* @see javax.servlet.Filter#destroy()
*/
public void destroy()
{
}
}