About RSA Public/Private Keys

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import com.chilkatsoft.*;

public class ChilkatExample {

  static {
    try {
        System.loadLibrary("chilkat");
    } catch (UnsatisfiedLinkError e) {
      System.err.println("Native code library failed to load.\n" + e);
      System.exit(1);
    }
  }

  public static void main(String argv[])
  {
    CkCert cert = new CkCert();

    boolean success;

    //  Load a digital certificate.
    success = cert.LoadFromFile("digitalCert.cer");
    if (success != true) {
        System.out.println(cert.lastErrorText());
        return;
    }

    CkPublicKey pubKey;

    //  A .cer file does not contain the private key.  It should contain
    //  the public key...
    pubKey = cert.ExportPublicKey();

    //  Let's have a look at it (in XML format).
    System.out.println("Public Key from Certificate:");
    System.out.println(pubKey.getXml());

    //  An RSA public key consists of a modulus and exponent.

    //  An RSA private key includes both the modulus and exponent,
    //  as well as other "big" numbers: P, Q, D, etc.

    //  Let's load an RSA private key from a DER-encoded file:
    CkPrivateKey privKey = new CkPrivateKey();

    success = privKey.LoadRsaDerFile("PrivateKey.key");
    if (success != true) {
        System.out.println(privKey.lastErrorText());
        return;
    }

    //  If this private key is the matching half to the public key from
    //  the certificate, then the modulus and exponent should
    //  be identical.  (Thus, a "private key" really contains both the public part as well as the private parts...).
    System.out.println("Private Key from DER:");
    System.out.println(privKey.getXml());

    CkRsa rsa = new CkRsa();
    success = rsa.UnlockComponent("Anything for 30-day trial.");
    if (success != true) {
        System.out.println(rsa.lastErrorText());
        return;
    }

    //  You now realize that the private key really contains both
    //  private and public parts.  Therefore, we may import the private
    //  key and the choose to use either the public or private in our
    //  encrypt/decrypt operations:
    String privKeyXml;
    privKeyXml = privKey.getXml();
    success = rsa.ImportPrivateKey(privKeyXml);
    if (success != true) {
        System.out.println(rsa.lastErrorText());
        return;
    }


  }
}