How to create OTP Generator using Java

 import java.util.*;

public class Eaglewebworld {

    static char[] OTP(int len){

        System.out.println("Generating OTP using random: ");

        System.out.print("Your OTP is :");

        String numbers="0123456789";

        Random rndm_method=new Random();

        char[] otp=new char[len];

        for(int i=0; i<len; i++){

            otp[i]=numbers.charAt(rndm_method.nextInt(numbers.length()));

        }

        return otp;

    }

    public static void main(String[] args){

        int length=4;

        System.out.println(OTP(length));

    }

}