WAS 6.0 - Response already committed / OutputStream already obtained

Question

Hello, we have struts code that is working fine in websphere 5, but not 6. I've seen this same kind of thing being post around, but haven't found one that closely resembles our simple setup. Below I've copied what our code looks like. Please help me to understand what the least-intrusive way would be to fix something simple like this, and let me know if more info is needed. FYI, we have tried returning null from the class, but this doens't seem to work. Also, some additional info is that we need this to work in WAS 5 and 6, because we have two different apps containing the same code, one of which is deployed (via EAR file) on 5 and the other 6. Thanks!
struts-config entry:     
<action path="/streamFile" type="MyClass" scope="request" validate="false">
              <forward name="success" path=""/>
</action>     
web.xml entry:
     <servlet-mapping>
          <servlet-name>opsconsoleServlet</servlet-name>
          <url-pattern>streamFile</url-pattern>
     </servlet-mapping>
Snippet of Class file:
public class MyClass extends Action {
     public ActionForward execute(ActionMapping mapping,
                     ActionForm form,
                    HttpServletRequest request,
                    HttpServletResponse response)
          throws Exception {    
     ServletOutputStream out = response.getOutputStream();
     BufferedOutputStream bos = null;
     try {
               bos = new BufferedOutputStream(out);
                bos.write(<bytes, etc>);
     } catch(final MalformedURLException e) {
     throw e;
     } catch(final IOException e) {
     throw e;
     } finally {
     if (bos != null)
          bos.close();
     if (out != null)
          out.close();
     return mapping.findForward("success");
error from log:
[11/5/07 12:50:11:737 EST] 00000036 ServletWrappe E   SRVE0014E: Uncaught service() exception root cause FilterProxyServlet: Cannot forward. Response already committed.
[11/5/07 12:50:12:001 EST] 00000036 ServletWrappe E   SRVE0068E: Could not invoke the service() method on servlet opsconsoleServlet. Exception thrown : javax.servlet.ServletException: Cannot forward. Response already committed.
        at com.ibm.ws.webcontainer.filter.WebAppFilterChain.doFilter(WebAppFilterChain.java:157)
        at com.ibm.ws.webcontainer.filter.WebAppFilterChain._doFilter(WebAppFilterChain.java:82)
error later in log:
[11/5/07 12:50:12:621 EST] 00000036 SRTServletRes W   WARNING: Cannot set status. Response already committed.
[11/5/07 12:50:12:627 EST] 00000036 SRTServletRes W   WARNING: Cannot set header. Response already committed.
[11/5/07 12:50:14:191 EST] 00000036 ServletWrappe A   SRVE0242I: [Communication] [/OpsConsole] [/WEB-INF/jsp/error/internalError.jsp]: Initialization successful.
[11/5/07 12:50:14:201 EST] 00000036 ServletWrappe E   SRVE0068E: Could not invoke the service() method on servlet /WEB-INF/jsp/error/internalError.jsp. Exception thrown : java.lang.IllegalStateException: SRVE0199E: OutputStream already obtained
        at com.ibm.ws.webcontainer.srt.SRTServletResponse.getWriter(SRTServletResponse.java:490)
        at org.apache.jasper.runtime.JspWriterImpl.initOut(JspWriterImpl.java:170)
        at org.apache.jasper.runtime.JspWriterImpl.flushBuffer(JspWriterImpl.java:163)
        at org.apache.jasper.runtime.PageContextImpl.release(PageContextImpl.java:227)

Answer 1

svguerin3 :
So this is something that worked in websphere 5 but not 6.. Are you sure this same code working on WAS5? This shouldn't. I guess you are trying to display the contents of the stream in a JSP page.If that's correct don't use
ServletOutputStream out = response.getOutputStream();
     BufferedOutputStream bos = null;
     try {
               bos = new BufferedOutputStream(out);
                bos.write(<bytes, etc>);
     }instead read the bytes in to an in memory object, add this in memory object to request param and then call findForward(). In the JSP page get this request attribute and do whatever you want.
Note: You can either use servletoutstream.write or RequestDispactcher.forward/redirect/response.sendRedirect.