ClassCastException

[Umi]

public static Object[] extendArraySize(Object[] o) {
        Object[] extended = new Object[o.length + 1];
        System.arraycopy(o, 0, extended, 0, o.length);
        return extended;
    }

Renamer[] renamer = new Renamer[4];
renamer = (Renamer[]) extendArraySize(renamer);

When running this, I get: Exception in thread "main" java.lang.ClassCastException: [Ljava.lang.Object; cannot be cast to [Lrenamefiles.Renamer;

Why do I get this?

Also, is it possible to pass a method as a parameter for another method?
For example in the use for calculating integrals.

[Fubarable]

You can't cast arrays like that. This looks like a situation where generics might help.

Better still: don't use arrays but rather the more flexible ArrayList which is already "genericized".

Edit: generics don't work well with arrays in that you can't create a generic array since type information doesn't exist at run time. You're far better off using an ArrayList here.

[AndreB]

your second question is can be solved by using interfaces