to flush a jsp

in order to test how a load balancer (F5 BIG-IP or Citrix Netscaler or others) time-outs an idle server or client, I cooked a simple JSP. what I desire is to flush any byte as soon it is written to the response stream. Using PERL, one'd set $| = 1; or autoflush(1) and be over with it. In an Apache/Tomcat environment, I ended up using <@ page buffer="none" %> and response.flushBuffer() combined. The API for 'buffer' page parameter led me believe it should accomplish what I desire by itself. It doesn't seem to be the case. Maybe it is buffered by Apache?