Web application (java servlets) best practices and performance

[Marcel Overdijk]

I'm currently evaluating Closure Templates as view layer in a java
servlet web application.

I'm wondering what the best practices is for compiling the templates.
I don't think the templates can be pre-compiled and provided to my
webapp in compiled format.
This would mean I have to compile them on application startup and
cache them.

But what I wonder about is the performance aspect. E.g. what would it
take to compile 1000+ templates?
I'm wondering this especially as I'm using Google App Engine and
startup times are really important as it spawns and kills instances
frequently.

Hope someone can shed the light on this.