How to Generate OTP in Java

Generating OTP in Java

In this example, we will show you simple program about, How to Generate OTP in Java. The example program has been tested and shared in the post.

Example Program

package com.dineshkrish;

/**
 * 
 * @author Dinesh Krishnan
 *
 */

public class OTP {

	private static int[] numbers = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };

	public static String getOTP(int size) {

		final StringBuffer otp = new StringBuffer();

		if (size != 0) {

			for (int i = 0; i < size; i++) {

				otp.append(numbers[(int) (Math.random() * numbers.length)]);
			}

			return otp.toString();
		}

		return "INVAILD";
	}

	public static void main(String[] args) {

		System.out.println(getOTP(4));
		System.out.println(getOTP(5));
		System.out.println(getOTP(6));
		System.out.println(getOTP(7));
		System.out.println(getOTP(8));
	}

}

Output

0418
19639
766684
0877528
49566906

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