如何在Java版本的Google App Engine中动态更新JSP文件的内容？

Question

I am currently teaching a software engineering class where approximately 275 students are learning JSP. I would like to be able to provide the students with an online service that enables them to practice their basic JSP skills. The idea is that students will provide some JSP code to pass some pre-determined tests.

For example: The students will be asked to provide the code for a JSP page that would return "Hello NAME" where NAME is a GET parameter that has been passed in to the page.

A correct response to this question would be.

Hello <%= request.getParameter("name") %>

I can currently test student submissions like this using a Linux-based solution where I write the submitted student code out to an existing JSP file, fetch the JSP page while passing in GET parameters, wait for Tomcat to reload and compile the JSP page, parse the HTML result, and return the test results to the students. This process is rather slow (overwriting JSP file on disk) and does not scale up well.

I'd like to be able to run this JSP "verifier" on the Java-version of Google App Engine which can be configured to scale up automatically when lots of students are practicing at the same time.

My question is, how can I evaluate submitted JSP code in Google App Engine without being able to overwrite the contents of an existing JSP file? Can I pass the code that I want to run to a JSP page and have that page return the results?

I can not figure out out to have the page use the passed in code to do something with the passed in GET parameters. In short, I'm missing an eval() method.

Any ideas?

Answer 1

I've never tried this, but I'd look at the Jasper Compiler (Tomcat's implementation of JSP). It can generate a class file from a .jsp, which you may be able to load from GAE. Though I could also imagine the required effort to get it working might be too much.