Generate KeyPair RSA In Java

RsaKeyPair.java

package com.example.rsagenerator;

import androidx.appcompat.app.AppCompatActivity;
import androidx.databinding.DataBindingUtil;

import android.os.Bundle;
import android.util.Base64;
import android.util.Log;
import android.view.View;

import com.example.rsagenerator.databinding.ActivityMainBinding;

import java.security.InvalidKeyException;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.NoSuchAlgorithmException;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.Signature;
import java.security.SignatureException;

public class MainActivity extends AppCompatActivity {

    ActivityMainBinding binding;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        binding = DataBindingUtil.setContentView(this, R.layout.activity_main);
    }

    public void generate(View view) {
        try {
            KeyPairGenerator kpg = KeyPairGenerator.getInstance("RSA");
            kpg.initialize(2048);

            KeyPair kp = kpg.genKeyPair();
            PublicKey publicKey = kp.getPublic();
            PrivateKey privateKey = kp.getPrivate();

            String pubKey = Base64.encodeToString(publicKey.getEncoded(), Base64.DEFAULT);
            String priKey = Base64.encodeToString(privateKey.getEncoded(), Base64.DEFAULT);

            binding.setRsa1(pubKey);
            binding.setRsa2(priKey);

            Log.d("publicKey", pubKey);
            Log.d("privateKey", priKey);

            String stringToSign = "Testing1|Testing2|Testing3";

            String signByte = signData(stringToSign.getBytes(), privateKey);
            Log.d("signByte", signByte);
            signVerify(stringToSign.getBytes(), publicKey, signByte);

        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        }
    }

    public static String signData (byte[] data, PrivateKey javaPrivateKey) {
        try {
            Signature s = Signature.getInstance("SHA256withRSA");
            s.initSign(javaPrivateKey);
            s.update(data);

            byte[] signature = s.sign();
            return Base64.encodeToString(signature , Base64.NO_WRAP);

        } catch (NoSuchAlgorithmException | SignatureException | InvalidKeyException e) {
            e.printStackTrace();
        }

        return null;
    }

    public static void signVerify (byte[] data, PublicKey javaPublicKey, String signature) {
        try {
            Signature s = Signature.getInstance("SHA256withRSA");
            s.initVerify(javaPublicKey);
            s.update(data);

            boolean success = s.verify(Base64.decode(signature, Base64.NO_WRAP));

            if(success) {
                Log.e("signVerify", "OK");
            } else {
                Log.e("signVerify", "FAILED");
            }
        } catch (NoSuchAlgorithmException | InvalidKeyException | SignatureException e) {
            e.printStackTrace();
        }
    }
}