Write a Java program to accept number from user and Calculate factorial of given number and Also check whether given number is prime or not. (Use Thread)

Write a Java program to accept number from user and Calculate factorial of given number and Also check whether given number is prime or not. (Use Thread)

Program:

import java.io.*;
import java.lang.*;

class FactPrime extends Thread {
    String str;
    int num1, num2, fact=1, flag=1, i;
    FactPrime(String s, int n) {
        num1 = n;
        str = s;
        setName(str);
        start();
    }

    public void run() {
        if(str.equals("First")) {
            try {
                for(i=1; i<=num1; i++) {
                    fact = fact*i;
                    sleep(500);
                }
                System.out.println("Factorial: "+fact);
            } catch (InterruptedException e) {
                System.out.println(e);
            }
        } else if(str.equals("Second")) {
            try {
                for(i=2;i<num1;i++) {
                    if(num1%i==0){
                        flag = 0;
                        break;
                    }
                    sleep(500);
                }
                if(flag==0){
                    System.out.println("Number is not Prime.");
                } else{
                    System.out.println("Number is Prime.");
                }
            } catch(InterruptedException e){
                System.out.println(e);
            }
        }
    }
}

class ThreadFactPrime {
    public static void main(String args[]) {
        int n,m;
        BufferedReader br =  new BufferedReader(new InputStreamReader(System.in));
        System.out.println("Enter the number to calculate Factorial:");
        n=Integer.parseInt(br.readLine());
        FactPrime t1 = new FactPrime("First",n);
        m=Integer.parseInt(br.readLine());
        FactPrime t2 = new FactPrime("Second",m);
    }
}