getOutputStream() has alredy been called exception

[radhesh]

I use MyFaces implementation of JSF
Now, when I try to use any of the Ajax4jsf components in my page, I get this "illlegalStateException; getOutputStream() has already been called.." exception.
The only reason I can think of is one of my filters forwarding the request (using request.forward) to the target resource (JSP or another servlet itself). Can this be the cause of this exception that the Ajax4jsf filter is not able to write to the response stream after the request has already been forwarded? Should I be using Request or Response wrappers in between?

In MyFaces scenario, where MyFacesExtension filter is also configured, what is the call sequence?

Thank you,
Rads

[svadu]

From what I know the #1 condition for ajax4jsf to work properly is to have the ajax4jsf filter to be first in your web.xml

[radhesh]

oh..sorry, I did not mention that...I have ajax4jsf as the first entry in my web.xml...!

[radhesh]

may be I can add one more pointer here..inspite of this exception in console, I am in fact getting the response page displayed in browser. However, the page does not seem to have the ajax4jsf javascripts being downloaded..so, now of the ajax actions work...:-(

[svadu]

I have ajax4jsf as the first entry in my web.xml

AFAIK if the ajax4jsf is first no other filter can forward the request because ajax4jsf gets the request first...

So this:

Can this be the cause of this exception that the Ajax4jsf filter is not able to write to the response stream after the request has already been forwarded?

is unlikely, imho

[sergeysmirnov]

Ajax4jsf filter checks for Servlet specification violations ( only one of output Writer or Stream can be used at the same time)

So, something in your application (or in other libraries) tries to ignore this restriction.

[radhesh]

u r right...but, the funny part is when I remove the a4j tags from the JSP page, I no longer get this exception and everything works fine...

[sergeysmirnov]

"SergeySmirnov" wrote:
Ajax4jsf filter checks for Servlet specification violations

How do you think, what Ajax4jsf does if the violation is detected ? :-/

[radhesh]

"SergeySmirnov" wrote:
Ajax4jsf filter checks for Servlet specification violations ( only one of output Writer or Stream can be used at the same time)

So, something in your application (or in other libraries) tries to ignore this restriction.

..thanks Sergey...I was also thinking in the same lines..but could not figure out the mistake at the first inspection...I guess I will have to go back and do somre more poking around to find the real culprit ...

[radhesh]

i am still stuck with this problem...So, let me explain the scenario again..I have configured Ajax4jsf filter as the first filter in my web app. Now, I have my own filter which needs to change the request URL and perform a forward (using requestdispatcher.forward). So, the filter chain breaks here and the response no longer goes through the Ajax4jsf filter.

Can someone please suggest a solution to this deadlock issue? I don't have any other option than to use forward from my own filter..and at the same time I need to be able to use Ajax4jsf as well...

[radhesh]

Found the solution..in case someone is interested
If you use *.jsp as the mapping for Ajax4jsf filter, things work just fine.