如何配置RSAKey.Builder以生成没有空值简单结果

import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.NoSuchAlgorithmException;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import org.bouncycastle.openssl.jcajce.JcaPEMKeyConverter;
import org.bouncycastle.openssl.jcajce.JcaPEMWriter;
import org.bouncycastle.util.io.pem.PemObject;
import org.bouncycastle.util.io.pem.PemWriter;

RSAKey.Builder builder = new RSAKey.Builder();
builder.keyLength(2048); // 设置密钥长度，可以根据需求进行调整
builder.keyUse(KeyUse.SIGNATURE); // 设置密钥用途，这里选择签名用途
builder.algorithm(KeyAlgorithm.RSA); // 设置算法，这里选择RSA算法
builder.keyID(UUID.randomUUID().toString()); // 设置密钥ID，可以根据需求进行调整

KeyPairGenerator keyPairGenerator;
try {
    keyPairGenerator = KeyPairGenerator.getInstance("RSA");
    keyPairGenerator.initialize(2048); // 设置密钥长度，与builder.keyLength保持一致
    KeyPair keyPair = keyPairGenerator.generateKeyPair();
    
    RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();
    RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();
    
    // 将公钥和私钥转换为PEM格式
    PemObject publicKeyObject = new PemObject("PUBLIC KEY", publicKey.getEncoded());
    PemObject privateKeyObject = new PemObject("PRIVATE KEY", privateKey.getEncoded());
    
    // 输出公钥和私钥
    try (PemWriter pemWriter = new PemWriter(new JcaPEMWriter(new OutputStreamWriter(System.out)))) {
        pemWriter.writeObject(publicKeyObject);
        pemWriter.writeObject(privateKeyObject);
    }
} catch (NoSuchAlgorithmException | IOException e) {
    e.printStackTrace();
}