如何读取用于OpenSAML的私钥？

keytool -genkey -alias mykey -keyalg RSA -keystore keystore.jks -keysize 2048

import java.security.Key;
import java.security.KeyPair;
import java.security.KeyStore;
import java.security.PrivateKey;
import java.security.cert.Certificate;
import java.security.cert.X509Certificate;

// ...

KeyStore keyStore = KeyStore.getInstance("JKS");
keyStore.load(new FileInputStream("keystore.jks"), "keystore-password".toCharArray());

Key key = keyStore.getKey("mykey", "key-password".toCharArray());
if (key instanceof PrivateKey) {
    PrivateKey privateKey = (PrivateKey) key;
    Certificate certificate = keyStore.getCertificate("mykey");
    X509Certificate x509Certificate = (X509Certificate) certificate;
    // 使用私钥和证书进行OpenSAML操作
}

import org.opensaml.security.credential.Credential;
import org.opensaml.security.credential.CredentialSupport;
import org.opensaml.security.x509.BasicX509Credential;

// ...

BasicX509Credential credential = new BasicX509Credential(privateKey, x509Certificate);
CredentialSupport.resolveSignatureAlgorithm(credential);