Re: jspc pre-compiler for Tomcat

["Alex Garrison" <agarriso@xxxxxxxxxxxxxxx>]

I believe you can change the behavior of the application class loaders to
use the native compile if desired.  Change the tomcat startup script to
include the property:

-Dos400.defineClass.optLevel=40

The following info is from the IBM Redbook SG24-6716-00, "HTTP Server
(powered by Apache) An Integrated Solution for IBM eserver iSeries Servers":

For untransformed Java objects that are in the iSeries system classpath (and
therefore
loaded through the system class loader), the os400.defineClass.optLevel
property can be
specified to cause the byte codes to be implicitly transformed. The
transformed version
persists across multiple instantiations of the Java Virtual Machine. Note
that if you specify this
property, performance may be slowed by creation of the hidden program the
first time you run
a Java program. For Java objects that are loaded through customized class
loaders (such as
the WebSphere Web application class loader), the os400.defineClass.optLevel
Java Virtual
Machine property will cause behavior similar to what the os400.optimization
property does
for Java objects in the system classpath. The main difference is that the
transformed version
is not saved. That is, each time the Java object is loaded, the
transformation occurs again.

As the document snippet states, the native objects implicitly created by the
application class loader would not persist when Tomcat was restarted.  You
would have to judge if the performance gain was worth it.

Alex Garrison