com.opencms.flex.cache
Class CmsFlexRequestDispatcher

java.lang.Object
  |
  +--com.opencms.flex.cache.CmsFlexRequestDispatcher

All Implemented Interfaces:

javax.servlet.RequestDispatcher

public class CmsFlexRequestDispatcher

extends Object

implements javax.servlet.RequestDispatcher

Implementation of the javax.servlet.RequestDispatcher interface to allow JSPs to be loaded from OpenCms.

This dispatcher will load data from 3 different data sources:

1. Form the "real" system Filesystem (e.g. for JSP pages)
2. From the OpenCms VFS
3. From the Flex cache

Version:

$Revision: 1.7.2.1 $

Author:

Alexander Kandzior (a.kandzior@alkacon.com)

Constructor Summary

CmsFlexRequestDispatcher(javax.servlet.RequestDispatcher rd, String vfs_target, String ext_target)
Creates a new instance of CmsFlexRequestDispatcher.

Method Summary

void	forward(javax.servlet.ServletRequest req, javax.servlet.ServletResponse res) Wrapper for the standard servlet API call.
void	include(javax.servlet.ServletRequest req, javax.servlet.ServletResponse res) Wrapper for dispatching to a file from the OpenCms VFS.

Methods inherited from class java.lang.Object

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

Constructor Detail

CmsFlexRequestDispatcher

public CmsFlexRequestDispatcher(javax.servlet.RequestDispatcher rd,
                                String vfs_target,
                                String ext_target)

Creates a new instance of CmsFlexRequestDispatcher.

Parameters:

rd - the "real" dispatcher, used for include call to file system

vfs_target - the cms resource that represents the external target

ext_target - the external target that the request will be dispatched to

Method Detail

forward

public void forward(javax.servlet.ServletRequest req,
                    javax.servlet.ServletResponse res)
             throws javax.servlet.ServletException,
                    IOException

Wrapper for the standard servlet API call.

Forward calls are actually NOT wrapped by OpenCms as of now. So they should not be used in JSP pages or servlets.

Specified by:

forward in interface javax.servlet.RequestDispatcher

Parameters:

req - the servlet request

res - the servlet response

Throws:

javax.servlet.ServletException - in case something goes wrong

IOException - in case something goes wrong

See Also:

RequestDispatcher.forward(javax.servlet.ServletRequest, javax.servlet.ServletResponse)

include

public void include(javax.servlet.ServletRequest req,
                    javax.servlet.ServletResponse res)
             throws javax.servlet.ServletException,
                    IOException

Wrapper for dispatching to a file from the OpenCms VFS.

This method will dispatch to cache, to real file system or to the OpenCms VFS, whatever is needed.

This method is much more complex then it sould be because of the internal standard buffering of JSP pages. Because of that I can not just intercept and buffer the stream, since I don't have access to it (it is wrapped internally in the JSP pages, which have their own buffer). That leads to a solution where the data is first written to the bufferd stream, but without includes. Then it is parsed again later (in response.processCacheEntry()), enriched with the included elements that have been ommitted in the first case. I would love to see a simpler solution, but this works for now.

Specified by:

include in interface javax.servlet.RequestDispatcher

Parameters:

req - the servlet request

res - the servlet response

Throws:

javax.servlet.ServletException - in case something goes wrong

IOException - in case something goes wrong