如何以编程方式(不使用Java KeyTool)生成密钥对并将其插入到KeyStore中？

import java.io.FileOutputStream;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.KeyStore;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.cert.Certificate;
import java.security.cert.CertificateFactory;
import java.security.cert.X509Certificate;

public class KeyStoreExample {
    public static void main(String[] args) throws Exception {
        // 生成密钥对
        KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("RSA");
        keyPairGenerator.initialize(2048);
        KeyPair keyPair = keyPairGenerator.generateKeyPair();
        PublicKey publicKey = keyPair.getPublic();
        PrivateKey privateKey = keyPair.getPrivate();

        // 创建KeyStore对象
        KeyStore keyStore = KeyStore.getInstance(KeyStore.getDefaultType());
        keyStore.load(null, null);

        // 生成证书
        X509Certificate cert = generateCertificate(publicKey, privateKey);

        // 将密钥对和证书存入KeyStore
        keyStore.setKeyEntry("mykey", privateKey, "password".toCharArray(), new Certificate[]{cert});

        // 保存KeyStore到文件
        FileOutputStream fos = new FileOutputStream("keystore.jks");
        keyStore.store(fos, "password".toCharArray());
        fos.close();
    }

    private static X509Certificate generateCertificate(PublicKey publicKey, PrivateKey privateKey) throws Exception {
        // 生成自签名证书
        X509Certificate cert = null;
        CertificateFactory certFactory = CertificateFactory.getInstance("X.509");
        cert = (X509Certificate) certFactory.generateCertificate(null);
        cert.verify(publicKey);
        return cert;
    }
}