Hello, codeforces community!

I am recently working on a project of building a Online Judge using Java and my minimum target was at least to make sure that it can detect the four most popular verdicts in Competitive Programming world. I somehow managed to implement AC, WA, TLE. But I am at a loss how to handle Runtime Error. For most of the cases, my program takes RE as TLE. I am just curious to know how can one determine Runtime Error effectively. I would love to have some idea about it and which can be a better a platform than CF community!

Thanks to all in advance.