GenerateRsaKeyPair.java

public class GenerateRsaKeyPair {
  public static void main(String args[]) {
    try {

      // 1. generate public key and private key
      KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("RSA");
      keyPairGenerator.initialize(1024); // key length
      KeyPair keyPair = keyPairGenerator.genKeyPair();
      String privateKeyString = Base64.encodeToString(keyPair.getPrivate().getEncoded(), Base64.DEFAULT);
      String publicKeyString = Base64.encodeToString(keyPair.getPublic().getEncoded(), Base64.DEFAULT);

      // 2. print both keys
      System.out.println("rsa key pair generated\n");
      System.out.println("privateKey\n" + privateKeyString + "\n");
      System.out.println("publicKey\n" + publicKeyString + "\n\n");

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