filters - getting IllegalStateException

[ankur rathi]

Hi,

I have a web.xml file which has filter mapping something like this:

<filter-mapping>
  <url-pattern>/mail/a/*</url-pattern>
  <filter-name>AFilter</filter-name>
</filter-mapping>
<filter-mapping>
  <url-pattern>/mail/a/b/*</url-pattern>
  <filter-name>ABFilter</filter-name>
</filter-mapping>
<filter-mapping>
  <url-pattern>/mail/a/c/*</url-pattern>
  <filter-name>ACFilter</filter-name>
</filter-mapping>

The code of filter class is something like this:

    
String url = request.getRequestURL();
url = url.replaceAll("one", "two");
response.sendRedirect(url);

All filter classes has same kind of code - they redirect to a URL.

I am getting an exception here:

    
java.lang.IllegalStateException: Cannot forward a response that is already committed
	at weblogic.servlet.internal.RequestDispatcherImpl.forward(RequestDispatcherImpl.java:110)
	at com.bea.netuix.servlets.manager.PortalServlet.handleOtherRequest(PortalServlet.java:1708)
	at com.bea.netuix.servlets.manager.PortalServlet.service(PortalServlet.java:714)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
	at weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSecurityHelper.java:226)
	Truncated. see log file for complete stacktrace
> 

This exception comes when we forward or include request after response is written.

I am not able to figure out what's happening here. Please help.

Thanks.

[Bauke Scholtz]

Simply don't run FilterChain#doFilter() or RequestDispatcher#forward() or RequestDispatcher#include() after the HttpServletResponse#sendRedirect() call.

[ankur rathi]

Bauke Scholtz wrote:Simply don't run FilterChain#doFilter() or RequestDispatcher#forward() or RequestDispatcher#include() after the HttpServletResponse#sendRedirect() call.

Thanks. But...

Consider a URL:

http://localhost:8001/mail/a/one

This would be redirected to:

http://localhost:8001/mail/a/two

It's the same pattern so filter called again and again and again...

It's not calling the next filter.

[Bauke Scholtz]

Just check the URL before replacing. If it is subject to replace, then replace and redirect, else continue with request.