Small Factorials, Java and big numbers

In the tutorial for the small factorials exercise: it states that there is built in support for dealing with large numbers in Java. My program does not work for testing 100. I read somewhere that there are classes that I can use to deal with such a large number of decimal places but I would really appreciate it if someone could point me in the right direction. I understand the tutorial but I would prefer to learn what I can use in Java instead of redesigning my program.

Thanks for any help!

You can use BigInteger, if you need, you can check my Java solution.


Thanks so much