Which is more secure: Tomcat standalone or Tomcat behind Apache?

Update 2021:
I dont like my old answer. I am not changing it. But I don't like it.

Before update 2010:

What would make Tomcat + Apache less secure?

  1. Larger surface of attack. More code is parsing the request. So there is larger chance that a security bug is encountered/exploited.
  2. More fixes to install, More configuration files to get correct and more security setting to get right. Greater chance to human error.

What would make Tomcat + Apache more secure?

Don't know.