In Java Programming

In mathematics, factorial of a non-negative integer n, denoted by n! , is the product of all positive integers less than or equal to n. For example,

5! = 5 * 4 * 3 * 2* 1 = 120

3! = 3 * 2 * 1 = 6

2! = 2 * 1 = 2

The value of 0! is 1.

Write a program that asks user to enter an integer > 0; if a valid value is entered, it should calculate and display factorial of the number entered. If the user enters an integer <=0, display a message "Invalid entry - valid entry is an integer > 0" and have them re-enter the information.