Comments on: Cool things: Automatic Online Interview Questions with Janino

By: Gil K

Gil K — Sun, 14 Sep 2008 13:48:33 +0000

Nice.
I like it!

By: stephan

stephan — Wed, 21 Nov 2007 20:33:13 +0000

As I said, “The nice thing with Java, compared to Ruby and PHP, is that Java has a fine grained security concept. With a Java security manager you can make this application safe by preventing access to file and system resoures and still execute the code the candidate entered into the form”

:-)

By: martind

martind — Wed, 21 Nov 2007 19:19:09 +0000

I may be stuck on a tangent here but — uh. pls don’t do that. either send them unit tests so they can run it locally while developing their solution; or make sure your compiled code is only executed in a heavily locked down sandbox. but don’t just allow people to post code and then blindly execute it on your machine.

By: stephan

stephan — Mon, 12 Nov 2007 10:51:28 +0000

@Paulo: “…but I was just stating that you could do the same by simply creating your own custom class loader.” And write a Java compiler on the go? Then I’d rather use Janino. I’m not sure if the Java 6 compiler API would also solve the problem.

Janino has such a class loader btw :-)

http://www.janino.net/use.html#class_loader

By: Paulo Abrantes

Paulo Abrantes — Mon, 12 Nov 2007 10:33:35 +0000

What simple classloader?

A simple custom classloader, which would load the string, compile it generating the bytecode and finally loading the class into memory. I know that’s what Janino does…but I was just stating that you could do the same by simply creating your own custom class loader.

By: stephan

stephan — Mon, 12 Nov 2007 05:58:34 +0000

What simple classloader?

You need a compiler to get the source to byte code, whereever the compiler is. And one of the simpliest compilers to use is Janino.

“The only problem I see in these sort of “tests” is that you have no proof that it was actually the candidate to answer your questions.”

As I said, you need a specific problem to solve, which he can’t find online for this to work. Perhaps a small percentage will ask a friend to solve the problem for him, but as this online questionaire is only the first step, you can judge later on if he’s a hire.

Yes most of the work will be done while interviewing.

By: Paulo Abrantes

Paulo Abrantes — Sun, 11 Nov 2007 22:24:42 +0000

It’s an interesting idea but instead of using Janino a simple custom class loader that would compile, load the class and run it against the unit tests would do, no?

While in the university there was a similar idea in one of the courses about algorithms. We would upload the source code (which was C not Java) and they would compile and run against a few tests that would then tell us if the code was correct and within the stipulated performance boundaries.

The only problem I see in these sort of “tests” is that you have no proof that it was actually the candidate to answer your questions. It probably will help you screen out a few candidates, but most of the work will still be done while reading CVs and interviewing… Don’t you think? (I never recruited people so my point of view might be a bit different from reality)