Programmatically invoke the JSP parser

Question

I would like to invoke the JSP parser programmatically. That means that I want to be able, in Java, to 'run' a jsp page and get its output, without sending it back to the client (I actually want to save the output to a file). I don't want to 'forward' the request to the JSP page. I want to be able to do that on several JSP pages in a row.

What is the best way of doing this?

I have found this question, but BalusC doesn't really answer the question directly.

In case you are wondering, I need to do this is because I want to 'precompile' the JSPs for using on other platforms than a Java servlet container.

EDIT

What I need is not the .class file, but the HTML output. Indeed, that will be static once generated but I have some custom jsp tags and I want to leverage the JSP parser to expand them.

Answer 1

I'm not sure that I understand the point of all this.

JSPs are parsed and precompiled to .class files. They're Java servlets at that point. You need a servlet engine to execute them.

If your intent is to capture the generated HTTP response as the "precompiled" response, it would suggest that there's no dynamic content and the response is the same every time you send that particular request. If that's the case, what you've got is static HTML.

If I'm correct, this would seem to be a poor way to generate such a thing.

If your wish is to precompile JSPs to .class files, the problem is that different Java EE app servers use different JSP precompilation engines. You can't precompile JSPs using Tomcat and use them on WebLogic.