How should I throw a divide by zero exception in Java without actually dividing by zero?

Question

I have an I2C device that wants two inputs: a denominator and a numerator. Both are written to separate addresses, so no actual calculation (numerator/denominator

Answer 1

You should not throw an ArithmeticException. Since the error is in the supplied arguments, throw an IllegalArgumentException. As the documentation says:

Thrown to indicate that a method has been passed an illegal or inappropriate argument.

Which is exactly what is going on here.

if (divisor == 0) {
    throw new IllegalArgumentException("Argument 'divisor' is 0");
}