This java program will read an integer numbers and find its prime factors, for example there is a number 60, its primer factors will be 2, 3 and 5 (that are not divisible by any other number).

package com.includehelp;

import java.util.HashSet;
import java.util.Scanner;
import java.util.Set;

/**
 * Program to find out prime factors of given number
 * @author includehelp
 */
public class PrimeFactors {
    
    /**
     * method to find prime factor for supplied number
     * @param number
     * @return 
     */
    static String getPrimeFactors(long number){
        Set<Integer> setPrimeFactors = new HashSet<>();  //set not Allowd Duplicate element
        for (int i = 2; i<= number; i++) {
            if (number % i == 0) {
                setPrimeFactors.add(i); // Add prime factor in Array List
                number = number/ i;
                i--;
                
            }
        }
        return setPrimeFactors.toString();
    }
    
    public static void main(String[] args) {
        Scanner sc  =   new Scanner(System.in);
        System.out.print("Enter Number  : ");
        int number =   sc.nextInt();
        
        System.out.println("Prime Factors of "+number+" is : "+getPrimeFactors(number));
    }
}

Output

Enter Number  : 60
Prime Factors of 60 is : [2, 3, 5]

Enter Number  : 1000
Prime Factors of 1000 is : [2, 5]