Discussion:
[FreeMarker-user] Passing parameters to included JSP files
Ionut Prunache
2012-10-17 13:06:30 UTC
Permalink
I'm working on a project for replacing an existing JSP code base with
Freemarker. I'm trying to do it progressively, that is I still want to be
able to include some JSP files from my new Freemarker templates.

The JSP pages that I include directly from .ftl files work fine, but there
is a problem when a JSP page included from an ftl tries to include another
JSP page and pass it some parameters. The second JSP file loads but doesn't
receive the parameters from the calling JSP, it only gets the parameters
that the .ftl passed to the first JSP.

Here is a short example of the flow:

page1.ftl
...
<@include_page path="/WEB-INF/jsp/page2.jsp" inherit_params=true
params={"param1": "param1"}/>
...

page2.jsp
...
<jsp:include page="/WEB-INF/page3.jsp">
<jsp:param name="param2" value="${someVar}"/>
</jsp:include>
...

request.getParameterNames() only contains param1 for both page2.jsp and
page3.jsp. I expect page3.jsp to see both param1 and param2.

Is there a way for this to work? If so, what am i doing wrong?

Thanks
Ionut
Ionut Prunache
2012-10-17 12:48:12 UTC
Permalink
I'm working on a project for replacing an existing JSP code base with
Freemarker. I'm trying to do it progressively, that is I still want to be
able to include some JSP files from my new Freemarker templates.

The JSP pages that I include directly from .ftl files work fine, but there
is a problem when a JSP page included from an ftl tries to include another
JSP page and pass it some parameters. The second JSP file loads but doesn't
receive the parameters from the calling JSP, it only gets the parameters
that the .ftl passed to the first JSP.

Here is a short example of the flow:

page1.ftl
...
<@include_page path="/WEB-INF/jsp/page2.jsp" inherit_params=true
params={"param1": "param1"}/>
...

page2.jsp
...
<jsp:include page="/WEB-INF/page3.jsp">
<jsp:param name="param2" value="${someVar}"/>
</jsp:include>
...

request.getParameterNames() only contains param1 for both page2.jsp and
page3.jsp. I expect page3.jsp to see both param1 and param2.

Is there a way for this to work? If so, what am i doing wrong?

Thanks
Ionut
Daniel Dekany
2012-10-17 16:12:14 UTC
Permalink
Post by Ionut Prunache
I'm working on a project for replacing an existing JSP code base
with Freemarker. I'm trying to do it progressively, that is I still
want to be able to include some JSP files from my new Freemarker templates.
The JSP pages that I include directly from .ftl files work fine,
but there is a problem when a JSP page included from an ftl tries to
include another JSP page and pass it some parameters. The second JSP
file loads but doesn't receive the parameters from the calling JSP,
it only gets the parameters that the .ftl passed to the first JSP.
page1.ftl
...
...
page2.jsp
...
<jsp:include page="/WEB-INF/page3.jsp">
<jsp:param name="param2" value="${someVar}"/>
</jsp:include>
...
request.getParameterNames() only contains param1 for both page2.jsp
and page3.jsp. I expect page3.jsp to see both param1 and param2.
Just to be sure, you are seeing "param1" only, in both page2.jsp and
page3.jsp, right? (When you try that, just print them, because
getParameterNames might have its own problems.) Then in page2.jsp, the
jsp:include didn't add "param2" to the request. That's the jsp:include
implementation's doing, and I don't see why it's happening. What's the
class of the request object in page2.jsp and in page3.jsp?
Post by Ionut Prunache
Is there a way for this to work? If so, what am i doing wrong?
Thanks
Ionut
--
Best regards,
Daniel Dekany
Ionut Prunache
2012-10-17 20:19:23 UTC
Permalink
Yes, that's correct, I'm only seeing "param1" in both page2.jsp and
page3.jsp. I should have mentioned that i'm using tomcat as application
server.

I found out why it's not working, at least for me, after some debugging.
The problem comes from the combination of Freemarker's CustomParamsRequest
and apache's implementation of request wrapping and forwarding.
CustomParamsRequest is used to wrap the page's HttpServletRequest and pass
parameters when performing an ftl include_page. It holds the parameters in
a map separated from the wrapped request that it only modifies at
Daniel Dekany
2012-10-18 07:56:21 UTC
Permalink
Post by Ionut Prunache
Yes, that's correct, I'm only seeing "param1" in both page2.jsp and
page3.jsp. I should have mentioned that i'm using tomcat as application server.
I found out why it's not working, at least for me, after some
debugging. The problem comes from the combination of Freemarker's
CustomParamsRequest and apache's implementation of request wrapping
and forwarding. CustomParamsRequest is used to wrap the page's
HttpServletRequest and pass parameters when performing an ftl
include_page. It holds the parameters in a map separated from the
wrapped request that it only modifies at construction time. From
then on it never updates that map, not even if the wrapped request gets changed.
And that's where it conflicts with apache's implementation.
Apache's implementation does not wrap around Freemarker's
CustomParamsRequest wrapper when performing an include, instead it
just creates a new ApplicationHttpRequest, it's request wrapper, and
replaces the request wrapped by CustomParamsRequest.
They don't create a new ServletRequestWrapper to wrap the original
request... the modify the current request. Ouch. But, the Servlet (and
JSP) sepc. is rather vague, so it's not like formally they violate
anything.
Post by Ionut Prunache
Because CustomParamsRequest never checks that it's request changes
and always serves it's initial parameters, any new parameters added
by the changes are never visible.
I managed to make it work by hacking CustomParamsRequest and
rebuilding freemarker.jar. I'm using this for now and i hope it's
good enough until i manage to complete the transition from JSP to ftl.
So what it should do is, checking if the wrapped request was replaced,
and if it was, re-build the internal parameter map. Right?
Post by Ionut Prunache
Post by Ionut Prunache
I'm working on a project for replacing an existing JSP code base
with Freemarker. I'm trying to do it progressively, that is I still
want to be able to include some JSP files from my new Freemarker templates.
The JSP pages that I include directly from .ftl files work fine,
but there is a problem when a JSP page included from an ftl tries to
include another JSP page and pass it some parameters. The second JSP
file loads but doesn't receive the parameters from the calling JSP,
it only gets the parameters that the .ftl passed to the first JSP.
page1.ftl
...
...
page2.jsp
...
<jsp:include page="/WEB-INF/page3.jsp">
<jsp:param name="param2" value="${someVar}"/>
</jsp:include>
...
request.getParameterNames() only contains param1 for both page2.jsp
and page3.jsp. I expect page3.jsp to see both param1 and param2.
Just to be sure, you are seeing "param1" only, in both page2.jsp and
page3.jsp, right? (When you try that, just print them, because
getParameterNames might have its own problems.) Then in page2.jsp, the
jsp:include didn't add "param2" to the request. That's the jsp:include
implementation's doing, and I don't see why it's happening. What's the
class of the request object in page2.jsp and in page3.jsp?
Post by Ionut Prunache
Is there a way for this to work? If so, what am i doing wrong?
Thanks
Ionut
--
Best regards,
Daniel Dekany
------------------------------------------------------------------------------
Everyone hates slow websites. So do we.
Make your web apps faster with AppDynamics
http://p.sf.net/sfu/appdyn_sfd2d_oct
_______________________________________________
FreeMarker-user mailing list
https://lists.sourceforge.net/lists/listinfo/freemarker-user
--
Best regards,
Daniel Dekany
Ionut Prunache
2012-10-18 08:18:33 UTC
Permalink
Yes, that's what i'm doing now, i invalidate the map when the request is
set and then rebuild it when a method needs it. It's kind of messy because
i have to take care not to include the params multiple time because each
include in an include chain would reset the request.
Post by Ionut Prunache
Post by Ionut Prunache
Yes, that's correct, I'm only seeing "param1" in both page2.jsp and
page3.jsp. I should have mentioned that i'm using tomcat as application
server.
Post by Ionut Prunache
I found out why it's not working, at least for me, after some
debugging. The problem comes from the combination of Freemarker's
CustomParamsRequest and apache's implementation of request wrapping
and forwarding. CustomParamsRequest is used to wrap the page's
HttpServletRequest and pass parameters when performing an ftl
include_page. It holds the parameters in a map separated from the
wrapped request that it only modifies at construction time. From
then on it never updates that map, not even if the wrapped request gets
changed.
Post by Ionut Prunache
And that's where it conflicts with apache's implementation.
Apache's implementation does not wrap around Freemarker's
CustomParamsRequest wrapper when performing an include, instead it
just creates a new ApplicationHttpRequest, it's request wrapper, and
replaces the request wrapped by CustomParamsRequest.
They don't create a new ServletRequestWrapper to wrap the original
request... the modify the current request. Ouch. But, the Servlet (and
JSP) sepc. is rather vague, so it's not like formally they violate
anything.
Post by Ionut Prunache
Because CustomParamsRequest never checks that it's request changes
and always serves it's initial parameters, any new parameters added
by the changes are never visible.
I managed to make it work by hacking CustomParamsRequest and
rebuilding freemarker.jar. I'm using this for now and i hope it's
good enough until i manage to complete the transition from JSP to ftl.
So what it should do is, checking if the wrapped request was replaced,
and if it was, re-build the internal parameter map. Right?
Post by Ionut Prunache
Post by Ionut Prunache
I'm working on a project for replacing an existing JSP code base
with Freemarker. I'm trying to do it progressively, that is I still
want to be able to include some JSP files from my new Freemarker
templates.
Post by Ionut Prunache
Post by Ionut Prunache
The JSP pages that I include directly from .ftl files work fine,
but there is a problem when a JSP page included from an ftl tries to
include another JSP page and pass it some parameters. The second JSP
file loads but doesn't receive the parameters from the calling JSP,
it only gets the parameters that the .ftl passed to the first JSP.
page1.ftl
...
params={"param1": "param1"}/>
Post by Ionut Prunache
Post by Ionut Prunache
...
page2.jsp
...
<jsp:include page="/WEB-INF/page3.jsp">
<jsp:param name="param2" value="${someVar}"/>
</jsp:include>
...
request.getParameterNames() only contains param1 for both page2.jsp
and page3.jsp. I expect page3.jsp to see both param1 and param2.
Just to be sure, you are seeing "param1" only, in both page2.jsp and
page3.jsp, right? (When you try that, just print them, because
getParameterNames might have its own problems.) Then in page2.jsp, the
jsp:include didn't add "param2" to the request. That's the jsp:include
implementation's doing, and I don't see why it's happening. What's the
class of the request object in page2.jsp and in page3.jsp?
Post by Ionut Prunache
Is there a way for this to work? If so, what am i doing wrong?
Thanks
Ionut
--
Best regards,
Daniel Dekany
------------------------------------------------------------------------------
Post by Ionut Prunache
Everyone hates slow websites. So do we.
Make your web apps faster with AppDynamics
http://p.sf.net/sfu/appdyn_sfd2d_oct
_______________________________________________
FreeMarker-user mailing list
https://lists.sourceforge.net/lists/listinfo/freemarker-user
--
Best regards,
Daniel Dekany
------------------------------------------------------------------------------
Everyone hates slow websites. So do we.
Make your web apps faster with AppDynamics
http://p.sf.net/sfu/appdyn_sfd2d_oct
_______________________________________________
FreeMarker-user mailing list
https://lists.sourceforge.net/lists/listinfo/freemarker-user
Daniel Dekany
2012-10-18 09:03:47 UTC
Permalink
Post by Ionut Prunache
Yes, that's what i'm doing now, i invalidate the map when the
request is set and then rebuild it when a method needs it. It's kind
of messy because i have to take care not to include the params
multiple time because each include in an include chain would reset the request.
I'm not sure I understand it well. I assume what we are talking about
is that when a jsp:include is called with jsp:param-s, the value(s) of
the params must be prepended before the values(s) of the already
existing params with the same name. For example, if you have p1=v1,
and then jsp:include has jsp:param p1=v2, then you should end up with
p1=[v2, v1] in the included file. But if I understand it well, you
said that they keep reusing the same single original
ServletRequestWrapper thorough all the nested jsp:include-s, and only
replace the wrapped ServletRequest for each. (And then, when the
inclusion has finised, they restore the previous wrapped
ServletRequest?) So how do they maintain the proper value order,
especially through multiple jsp:includes? Do the param values coming
from that single shared ServletRequestWrapper always appear at the end
of the parameter value lists (the opposite of what FM does...), and
all the params coming from jsp:include-s are coming from the wrapped
ApplicationHttpRequest-s, which have, somehow, has the params coming
from jsp:includes in the proper order? (How are the new
ApplicationHttpRequest initialized anyway? Do they get the inherited
values from the replaced wrapped HttpRequest?)
Post by Ionut Prunache
Post by Ionut Prunache
Yes, that's correct, I'm only seeing "param1" in both page2.jsp and
page3.jsp. I should have mentioned that i'm using tomcat as application server.
I found out why it's not working, at least for me, after some
debugging. The problem comes from the combination of Freemarker's
CustomParamsRequest and apache's implementation of request wrapping
and forwarding. CustomParamsRequest is used to wrap the page's
HttpServletRequest and pass parameters when performing an ftl
include_page. It holds the parameters in a map separated from the
wrapped request that it only modifies at construction time. From
then on it never updates that map, not even if the wrapped request gets changed.
And that's where it conflicts with apache's implementation.
Apache's implementation does not wrap around Freemarker's
CustomParamsRequest wrapper when performing an include, instead it
just creates a new ApplicationHttpRequest, it's request wrapper, and
replaces the request wrapped by CustomParamsRequest.
They don't create a new ServletRequestWrapper to wrap the original
request... the modify the current request. Ouch. But, the Servlet (and
JSP) sepc. is rather vague, so it's not like formally they violate
anything.
Post by Ionut Prunache
Because CustomParamsRequest never checks that it's request changes
and always serves it's initial parameters, any new parameters added
by the changes are never visible.
I managed to make it work by hacking CustomParamsRequest and
rebuilding freemarker.jar. I'm using this for now and i hope it's
good enough until i manage to complete the transition from JSP to ftl.
So what it should do is, checking if the wrapped request was replaced,
and if it was, re-build the internal parameter map. Right?
Post by Ionut Prunache
Post by Ionut Prunache
I'm working on a project for replacing an existing JSP code base
with Freemarker. I'm trying to do it progressively, that is I still
want to be able to include some JSP files from my new Freemarker templates.
The JSP pages that I include directly from .ftl files work fine,
but there is a problem when a JSP page included from an ftl tries to
include another JSP page and pass it some parameters. The second JSP
file loads but doesn't receive the parameters from the calling JSP,
it only gets the parameters that the .ftl passed to the first JSP.
page1.ftl
...
...
page2.jsp
...
<jsp:include page="/WEB-INF/page3.jsp">
<jsp:param name="param2" value="${someVar}"/>
</jsp:include>
...
request.getParameterNames() only contains param1 for both page2.jsp
and page3.jsp. I expect page3.jsp to see both param1 and param2.
Just to be sure, you are seeing "param1" only, in both page2.jsp and
page3.jsp, right? (When you try that, just print them, because
getParameterNames might have its own problems.) Then in page2.jsp, the
jsp:include didn't add "param2" to the request. That's the jsp:include
implementation's doing, and I don't see why it's happening. What's the
class of the request object in page2.jsp and in page3.jsp?
Post by Ionut Prunache
Is there a way for this to work? If so, what am i doing wrong?
Thanks
Ionut
--
Best regards,
Daniel Dekany
------------------------------------------------------------------------------
Everyone hates slow websites. So do we.
Make your web apps faster with AppDynamics
http://p.sf.net/sfu/appdyn_sfd2d_oct
_______________________________________________
FreeMarker-user mailing list
https://lists.sourceforge.net/lists/listinfo/freemarker-user
--
Best regards,
Daniel Dekany
------------------------------------------------------------------------------
Everyone hates slow websites. So do we.
Make your web apps faster with AppDynamics
http://p.sf.net/sfu/appdyn_sfd2d_oct
_______________________________________________
FreeMarker-user mailing list
https://lists.sourceforge.net/lists/listinfo/freemarker-user
--
Best regards,
Daniel Dekany
Ionut Prunache
2012-10-18 09:17:25 UTC
Permalink
After a closer look i think they do not just overwrite the wrapped
HttpRequest. They build a request chain of ApplicationHttpRequests and the
head of this chain is set as the wrapped request in Freemarker's wrapper.
So they manage the parameters correctly, as you expect, but just put them
under the CustomParamsRequest and thus render them invisible.

When they add a new request they go down the request chain until they find
a familiar wrapper, which CustomParamsRequest isn't, and then wrap the
request around that wrapper. That's what i could figure with a little
debugging. I'm just starting to use Freemarker and Java Enterprise so i
don't have much experience with these things.

Best Regads,
Ionut Prunache
Post by Ionut Prunache
Post by Ionut Prunache
Yes, that's what i'm doing now, i invalidate the map when the
request is set and then rebuild it when a method needs it. It's kind
of messy because i have to take care not to include the params
multiple time because each include in an include chain would reset the
request.
I'm not sure I understand it well. I assume what we are talking about
is that when a jsp:include is called with jsp:param-s, the value(s) of
the params must be prepended before the values(s) of the already
existing params with the same name. For example, if you have p1=v1,
and then jsp:include has jsp:param p1=v2, then you should end up with
p1=[v2, v1] in the included file. But if I understand it well, you
said that they keep reusing the same single original
ServletRequestWrapper thorough all the nested jsp:include-s, and only
replace the wrapped ServletRequest for each. (And then, when the
inclusion has finised, they restore the previous wrapped
ServletRequest?) So how do they maintain the proper value order,
especially through multiple jsp:includes? Do the param values coming
from that single shared ServletRequestWrapper always appear at the end
of the parameter value lists (the opposite of what FM does...), and
all the params coming from jsp:include-s are coming from the wrapped
ApplicationHttpRequest-s, which have, somehow, has the params coming
from jsp:includes in the proper order? (How are the new
ApplicationHttpRequest initialized anyway? Do they get the inherited
values from the replaced wrapped HttpRequest?)
Post by Ionut Prunache
Post by Ionut Prunache
Yes, that's correct, I'm only seeing "param1" in both page2.jsp and
page3.jsp. I should have mentioned that i'm using tomcat as application
server.
Post by Ionut Prunache
Post by Ionut Prunache
I found out why it's not working, at least for me, after some
debugging. The problem comes from the combination of Freemarker's
CustomParamsRequest and apache's implementation of request wrapping
and forwarding. CustomParamsRequest is used to wrap the page's
HttpServletRequest and pass parameters when performing an ftl
include_page. It holds the parameters in a map separated from the
wrapped request that it only modifies at construction time. From
then on it never updates that map, not even if the wrapped request gets
changed.
Post by Ionut Prunache
Post by Ionut Prunache
And that's where it conflicts with apache's implementation.
Apache's implementation does not wrap around Freemarker's
CustomParamsRequest wrapper when performing an include, instead it
just creates a new ApplicationHttpRequest, it's request wrapper, and
replaces the request wrapped by CustomParamsRequest.
They don't create a new ServletRequestWrapper to wrap the original
request... the modify the current request. Ouch. But, the Servlet (and
JSP) sepc. is rather vague, so it's not like formally they violate
anything.
Post by Ionut Prunache
Because CustomParamsRequest never checks that it's request changes
and always serves it's initial parameters, any new parameters added
by the changes are never visible.
I managed to make it work by hacking CustomParamsRequest and
rebuilding freemarker.jar. I'm using this for now and i hope it's
good enough until i manage to complete the transition from JSP to ftl.
So what it should do is, checking if the wrapped request was replaced,
and if it was, re-build the internal parameter map. Right?
Post by Ionut Prunache
Post by Ionut Prunache
I'm working on a project for replacing an existing JSP code base
with Freemarker. I'm trying to do it progressively, that is I still
want to be able to include some JSP files from my new Freemarker
templates.
Post by Ionut Prunache
Post by Ionut Prunache
Post by Ionut Prunache
The JSP pages that I include directly from .ftl files work fine,
but there is a problem when a JSP page included from an ftl tries to
include another JSP page and pass it some parameters. The second JSP
file loads but doesn't receive the parameters from the calling JSP,
it only gets the parameters that the .ftl passed to the first JSP.
page1.ftl
...
params={"param1": "param1"}/>
Post by Ionut Prunache
Post by Ionut Prunache
Post by Ionut Prunache
...
page2.jsp
...
<jsp:include page="/WEB-INF/page3.jsp">
<jsp:param name="param2" value="${someVar}"/>
</jsp:include>
...
request.getParameterNames() only contains param1 for both page2.jsp
and page3.jsp. I expect page3.jsp to see both param1 and param2.
Just to be sure, you are seeing "param1" only, in both page2.jsp and
page3.jsp, right? (When you try that, just print them, because
getParameterNames might have its own problems.) Then in page2.jsp, the
jsp:include didn't add "param2" to the request. That's the jsp:include
implementation's doing, and I don't see why it's happening. What's the
class of the request object in page2.jsp and in page3.jsp?
Post by Ionut Prunache
Is there a way for this to work? If so, what am i doing wrong?
Thanks
Ionut
--
Best regards,
Daniel Dekany
------------------------------------------------------------------------------
Post by Ionut Prunache
Post by Ionut Prunache
Everyone hates slow websites. So do we.
Make your web apps faster with AppDynamics
http://p.sf.net/sfu/appdyn_sfd2d_oct
_______________________________________________
FreeMarker-user mailing list
https://lists.sourceforge.net/lists/listinfo/freemarker-user
--
Best regards,
Daniel Dekany
------------------------------------------------------------------------------
Post by Ionut Prunache
Everyone hates slow websites. So do we.
Make your web apps faster with AppDynamics
http://p.sf.net/sfu/appdyn_sfd2d_oct
_______________________________________________
FreeMarker-user mailing list
https://lists.sourceforge.net/lists/listinfo/freemarker-user
--
Best regards,
Daniel Dekany
------------------------------------------------------------------------------
Everyone hates slow websites. So do we.
Make your web apps faster with AppDynamics
http://p.sf.net/sfu/appdyn_sfd2d_oct
_______________________________________________
FreeMarker-user mailing list
https://lists.sourceforge.net/lists/listinfo/freemarker-user
Daniel Dekany
2012-10-18 11:17:45 UTC
Permalink
Post by Ionut Prunache
After a closer look i think they do not just overwrite the wrapped
HttpRequest. They build a request chain of ApplicationHttpRequests
and the head of this chain is set as the wrapped request in
Freemarker's wrapper. So they manage the parameters correctly, as
you expect, but just put them under the CustomParamsRequest and thus render them invisible.
When they add a new request they go down the request chain until
they find a familiar wrapper, which CustomParamsRequest isn't, and
then wrap the request around that wrapper.
So, when there's no FreeMarker around, just pure JSP, the the initial
inclusion doesn't call ServletRequestWrapper.setServletRequest
anywhere, just wraps the current ServletRequest? That's the obvious
way of doing this, and it's also what FreeMarker's servlet-inclusion
does BTW. If jsp:include was doing the same with the
CustomParamsRequest (and why not, it's just a ServletRequestWrapper),
there wouldn't be any problems... Anyway, I hoped there's some trivial
fix, but it seems it's more involved to figure out.
Post by Ionut Prunache
That's what i could figure with a little debugging. I'm just
starting to use Freemarker and Java Enterprise so i don't have much
experience with these things.
Best Regads,
Ionut Prunache
Post by Ionut Prunache
Yes, that's what i'm doing now, i invalidate the map when the
request is set and then rebuild it when a method needs it. It's kind
of messy because i have to take care not to include the params
multiple time because each include in an include chain would reset the request.
I'm not sure I understand it well. I assume what we are talking about
is that when a jsp:include is called with jsp:param-s, the value(s) of
the params must be prepended before the values(s) of the already
existing params with the same name. For example, if you have p1=v1,
and then jsp:include has jsp:param p1=v2, then you should end up with
p1=[v2, v1] in the included file. But if I understand it well, you
said that they keep reusing the same single original
ServletRequestWrapper thorough all the nested jsp:include-s, and only
replace the wrapped ServletRequest for each. (And then, when the
inclusion has finised, they restore the previous wrapped
ServletRequest?) So how do they maintain the proper value order,
especially through multiple jsp:includes? Do the param values coming
from that single shared ServletRequestWrapper always appear at the end
of the parameter value lists (the opposite of what FM does...), and
all the params coming from jsp:include-s are coming from the wrapped
ApplicationHttpRequest-s, which have, somehow, has the params coming
from jsp:includes in the proper order? (How are the new
ApplicationHttpRequest initialized anyway? Do they get the inherited
values from the replaced wrapped HttpRequest?)
Post by Ionut Prunache
Post by Ionut Prunache
Yes, that's correct, I'm only seeing "param1" in both page2.jsp and
page3.jsp. I should have mentioned that i'm using tomcat as application server.
I found out why it's not working, at least for me, after some
debugging. The problem comes from the combination of Freemarker's
CustomParamsRequest and apache's implementation of request wrapping
and forwarding. CustomParamsRequest is used to wrap the page's
HttpServletRequest and pass parameters when performing an ftl
include_page. It holds the parameters in a map separated from the
wrapped request that it only modifies at construction time. From
then on it never updates that map, not even if the wrapped request gets changed.
And that's where it conflicts with apache's implementation.
Apache's implementation does not wrap around Freemarker's
CustomParamsRequest wrapper when performing an include, instead it
just creates a new ApplicationHttpRequest, it's request wrapper, and
replaces the request wrapped by CustomParamsRequest.
They don't create a new ServletRequestWrapper to wrap the original
request... the modify the current request. Ouch. But, the Servlet (and
JSP) sepc. is rather vague, so it's not like formally they violate
anything.
Post by Ionut Prunache
Because CustomParamsRequest never checks that it's request changes
and always serves it's initial parameters, any new parameters added
by the changes are never visible.
I managed to make it work by hacking CustomParamsRequest and
rebuilding freemarker.jar. I'm using this for now and i hope it's
good enough until i manage to complete the transition from JSP to ftl.
So what it should do is, checking if the wrapped request was replaced,
and if it was, re-build the internal parameter map. Right?
Post by Ionut Prunache
Post by Ionut Prunache
I'm working on a project for replacing an existing JSP code base
with Freemarker. I'm trying to do it progressively, that is I still
want to be able to include some JSP files from my new Freemarker templates.
The JSP pages that I include directly from .ftl files work fine,
but there is a problem when a JSP page included from an ftl tries to
include another JSP page and pass it some parameters. The second JSP
file loads but doesn't receive the parameters from the calling JSP,
it only gets the parameters that the .ftl passed to the first JSP.
page1.ftl
...
...
page2.jsp
...
<jsp:include page="/WEB-INF/page3.jsp">
<jsp:param name="param2" value="${someVar}"/>
</jsp:include>
...
request.getParameterNames() only contains param1 for both page2.jsp
and page3.jsp. I expect page3.jsp to see both param1 and param2.
Just to be sure, you are seeing "param1" only, in both page2.jsp and
page3.jsp, right? (When you try that, just print them, because
getParameterNames might have its own problems.) Then in page2.jsp, the
jsp:include didn't add "param2" to the request. That's the jsp:include
implementation's doing, and I don't see why it's happening. What's the
class of the request object in page2.jsp and in page3.jsp?
Post by Ionut Prunache
Is there a way for this to work? If so, what am i doing wrong?
Thanks
Ionut
--
Best regards,
Daniel Dekany
------------------------------------------------------------------------------
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Best regards,
Daniel Dekany
------------------------------------------------------------------------------
Everyone hates slow websites. So do we.
Make your web apps faster with AppDynamics
http://p.sf.net/sfu/appdyn_sfd2d_oct
_______________________________________________
FreeMarker-user mailing list
https://lists.sourceforge.net/lists/listinfo/freemarker-user
--
Best regards,
Daniel Dekany
------------------------------------------------------------------------------
Everyone hates slow websites. So do we.
Make your web apps faster with AppDynamics
http://p.sf.net/sfu/appdyn_sfd2d_oct
_______________________________________________
FreeMarker-user mailing list
https://lists.sourceforge.net/lists/listinfo/freemarker-user
--
Best regards,
Daniel Dekany
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