Why doesn't catching Exception catch RuntimeException?

The premise of the question is flawed, because catching Exception does catch RuntimeException. Demo code:

public class Test {
    public static void main(String[] args) {
        try {
            throw new RuntimeException("Bang");
        } catch (Exception e) {
            System.out.println("I caught: " + e);
        }
    }
}

Output:

I caught: java.lang.RuntimeException: Bang

Your loop will have problems if:

• callbacks is null
• anything modifies callbacks while the loop is executing (if it were a collection rather than an array)

Perhaps that's what you're seeing?

catch (Exception ex) { ... }

WILL catch RuntimeException.

Whatever you put in catch block will be caught as well as the subclasses of it.

Catching Exception will catch a RuntimeException