How to check whether input value is integer or float?

How about this. using the modulo operator

if(a%b==0) 
{
    System.out.println("b is a factor of a. i.e. the result of a/b is going to be an integer");
}
else
{
    System.out.println("b is NOT a factor of a");
}

You should check that fractional part of the number is 0. Use

x==Math.ceil(x)

or

x==Math.round(x)

or something like that