PK90190; 6.0.2.35: com.ibm.wsspi.jsp.cdatatrim=true breaks using servlet caching

Download Description

PK90190 resolves the following problem:

ERROR DESCRIPTION:
Setting the custom property com.ibm.wsspi.jsp.usecdatatrim=true on the web container in WebSphere Application Server causes problems when using servlet caching with the Dynamic cache.

LOCAL FIX:
A simple workaround to this problem would be to simply write a space before the first out.flush in JSP.

PROBLEM SUMMARY

USERS AFFECTED:
IBM WebSphere Application Server Version 6.0.2, 6.1 and 7.0 users of DynaCache.

PROBLEM DESCRIPTION:
Duplicate content can be displayed for a JavaServer Page (JSP) file when DynaCache is enabled and the useCDataTrim JSP attribute is set to true.

RECOMMENDATION:
None

Duplicate content can be displayed for a JSP file on a cache hit when the useCDataTrim JSP attribute is set to true. The duplicate content is caused by the interaction of the JSP buffer and the DynaCache writer during an include.

PROBLEM CONCLUSION:
The JSP Engine was modified to get the response writer even if there are zero bytes to flush. This new behavior is enabled by setting the following WebContainer custom property to "true":
com.ibm.ws.jsp.getWriterOnEmptyBuffer
Please refer to the following technote for instructions on enabling WebContainer custom properties:
http://www.ibm.com/support/docview.wss?uid=swg21284395

The fix for this APAR is currently targeted for inclusion in fix packs 6.0.2.39, 6.1.0.29, and 7.0.0.7. Please refer to the Recommended Updates page for delivery information:
http://www.ibm.com/support/docview.wss?uid=swg27004980