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 $

Author:

Alexander Kandzior (a.kandzior@alkacon.com)

Constructor Summary

CmsFlexRequestDispatcher(javax.servlet.RequestDispatcher rd, String target, CmsFlexCache cache, CmsObject cms)
Creates a new instance of CmsFlexRequestDispatcher.

CmsFlexRequestDispatcher(javax.servlet.RequestDispatcher rd, String target, String ext_target, CmsFlexCache cache, CmsObject cms)
Creates a new instance of CmsFlexRequestDispatcher.

Method Summary

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

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 target,
                                CmsFlexCache cache,
                                CmsObject cms)

Creates a new instance of CmsFlexRequestDispatcher.

Parameters:

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

target - the target that the request will be dispatched to

cache - the cache used for delivering and storing of cached pages

cms - the CmsObject that is needed for authorization of internal calls to the OpenCms VFS<

CmsFlexRequestDispatcher

public CmsFlexRequestDispatcher(javax.servlet.RequestDispatcher rd,
                                String target,
                                String ext_target,
                                CmsFlexCache cache,
                                CmsObject cms)

Creates a new instance of CmsFlexRequestDispatcher.

Parameters:

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

target - the cms resource that represents the external target

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

cache - the cache used for delivering and storing of cached pages

cms - the CmsObject that is needed for authorization of internal calls to the OpenCms VFS

Method Detail

forward

public void forward(javax.servlet.ServletRequest servletRequest,
                    javax.servlet.ServletResponse servletResponse)
             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:

servletRequest - the servlet request

servletResponse - 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 servletRequest,
                    javax.servlet.ServletResponse servletResponse)
             throws javax.servlet.ServletException,
                    IOException

Wrapper for the standard servlet API call.

If you use standard include(), the call will be done by the standard request dispatcher. In case you want to include somthing from the Cms VFS, use includeFromCms() instead.

Specified by:

include in interface javax.servlet.RequestDispatcher

Parameters:

servletRequest - The servlet request

servletResponse - The servlet response

Throws:

javax.servlet.ServletException - In case something goes wrong

IOException - In case something goes wrong

See Also:

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

include

public void include(CmsFlexRequest req,
                    CmsFlexResponse res)
             throws javax.servlet.ServletException,
                    IOException

Wrapper for dispatching to a file from the OpenCms VFS.

It was choosen NOT to overload the standard API include() call, since standard JSP might expect the standard behaviour from the RequestDispatcher, i.e. loading the files form the file system.

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.

Parameters:

req - the servlet request

res - the servlet response

Throws:

javax.servlet.ServletException - in case something goes wrong

IOException - in case something goes wrong