Tomcat 7.0 uses the Jasper 2 JSP Engine to implement
the JavaServer Pages 2.2
specification.
Jasper 2 has been redesigned to significantly improve performance over
the original Jasper. In addition to general code improvements the following
changes were made:
- JSP Custom Tag Pooling - The java objects instantiated
for JSP Custom Tags can now be pooled and reused. This significantly boosts
the performance of JSP pages which use custom tags.
- Background JSP compilation - If you make a change to
a JSP page which had already been compiled Jasper 2 can recompile that
page in the background. The previously compiled JSP page will still be
available to serve requests. Once the new page has been compiled
successfully it will replace the old page. This helps improve availability
of your JSP pages on a production server.
- Recompile JSP when included page changes - Jasper 2
can now detect when a page included at compile time from a JSP has changed
and then recompile the parent JSP.
- JDT used to compile JSP pages - The
Eclipse JDT Java compiler is now used to perform JSP java source code
compilation. This compiler loads source dependencies from the container
classloader. Ant and javac can still be used.
Jasper is implemented using the servlet class
org.apache.jasper.servlet.JspServlet
.