There are a couple of small bugs in the compression filter classes that are triggered by using the filter in WebSphere 5.1 or 6. Here are patches. - CompressionResponseStream should not compress the output stream if the response has been committed (because then it cannot write the Content-Encoding: gzip header, and the browser displays the compressed output as-is) - CompressionServletResponseWrapper causes a NullPointerException if you flush before writing anything
Created attachment 18266 [details] patch to not compress committed response stream
Created attachment 18267 [details] avoid NullPointerException when flushing before writing
Many thanks for the patches. The NPE had already been fixed. I applied the remaining patch to svn and it will be included in 5.5.21 onwards.