java.math.BigInteger cannot be cast to java.lang.Integer

Question

I\'m getting the following exception.

Caused by:

java.lang.ClassCastException: java.math.BigInteger cannot be cast to java.lang.Integer

Answer 1

As we see from the javaDoc, BigInteger is not a subclass of Integer:

java.lang.Object                      java.lang.Object
   java.lang.Number                       java.lang.Number
      java.math.BigInteger                    java.lang.Integer

And that's the reason why casting from BigInteger to Integer is impossible.

Casting of java primitives will do some conversion (like casting from double to int) while casting of types will never transform classes.