This is one of several reasons why major systems moved to Java.
So some people are /still/ using Ruby for software systems especially the security bug feast called Ruby on Rails, WTF!
Dynamic typed languages like Ruby and Python are fine for limited scripting, but not smart for larger programs, especially when they can become write-only code due to unknown interface typing and meta-programming confusion!
Any kind of duck typing is liable to type ambiguity/abuse and any lack of strong typing of declared function/method parameters can easily become a quite stupid ticking bug-bomb, because it can make automated/manual analysis/re-factoring/testing/runtime-optimisation much harder and/or much less reliable!
A lot of these kinds of vulnerabilities can be detected in Java by IDE source editors and existing compilers, and most of the rest get detected by the mature static analysis tools Java has had for several years now, including FindBugs and PMD.