How to generate secret key using SecureRandom.getInstanceStrong()?

How to generate secret key using SecureRandom.getInstanceStrong()?

With this code I can receive byte array with random values. Is there any easy way to generate key of a given length (256 bits, for example), type (int, String) and format (hex, bin, dec)?

package com.company;

import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;

public class KeyGen {

    public void generate() throws NoSuchAlgorithmException {

        SecureRandom random = SecureRandom.getInstanceStrong();
        byte[] values = new byte[32]; // 256 bit
        random.nextBytes(values);

        StringBuilder sb = new StringBuilder();
        for (byte b : values) {
            sb.append(String.format("%02x", b));
        }
        System.out.print("Key: ");
        System.out.println(sb.toString());
    }
}

Output:

Key: 8fcea84897f48f575c22441ece4e7ddb43ac08cd2c1a83fca46c080768468059