Write a method that calculates the factorial of a given number. Factorial is the product of all positive integers less than or equal to n. For example, factorial(4) = 4x3x2x1 = 24. TIP: To make it more interesting, try to do it recursively. public Integer factorial(Integer n) { int factorial = n; for (int j=n-1;j> 0; j--) { factorial factorial *j; } } return factorial; Input(n) 1 6 8