如何在Java中从PGP公钥中获取用户id？

我使用PGP加密文件，然后使用ApacheCamel进行传输。我能够使用加密和解密

我需要提供

KeyUserId

和公钥。我想从公钥中提取此用户id

$ gpg --import 0x6E1A09A4-pub.asc                    

gpg: key 6E1A09A4: public key "User <user@domain.com>" imported
gpg: Total number processed: 1
gpg:               imported: 1  (RSA: 1)

$gpg--导入0x6E1A09A4-pub.asc
gpg:密钥6E1A09A4:已导入公钥“用户”
gpg:处理的总数：1
gpg:imported:1（RSA:1）

如果我使用

gpg

命令行cli导入它，它将显示用户ID。在java中，如何从公钥中获取用户ID

private PGPPublicKey getPGPPublicKey(String filePath) throws IOException, PGPException {
    InputStream inputStream = new BufferedInputStream(new FileInputStream(filePath));
    PGPPublicKeyRingCollection pgpPublicKeyRingCollection = new PGPPublicKeyRingCollection(PGPUtil.getDecoderStream(inputStream), new JcaKeyFingerprintCalculator());
    Iterator keyRingIterator = pgpPublicKeyRingCollection.getKeyRings();
    while (keyRingIterator.hasNext()) {
        PGPPublicKeyRing keyRing = (PGPPublicKeyRing) keyRingIterator.next();
        Iterator keyIterator = keyRing.getPublicKeys();
        while (keyIterator.hasNext()) {
            PGPPublicKey key = (PGPPublicKey) keyIterator.next();
            if (key.isEncryptionKey()) {
                return key;
            }
        }
    }
    inputStream.close();
    throw new IllegalArgumentException("Can't find encryption key in key ring.");
}

private String getUserId(String publicKeyFile) throws IOException, PGPException {
    PGPPublicKey pgpPublicKey = getPGPPublicKey(publicKeyFile);
    // You can iterate and return all the user ids if needed
    return (String) pgpPublicKey.getUserIDs().next();
}

private PGPPublicKey getPGPPublicKey(String filePath) throws IOException, PGPException {
    InputStream inputStream = new BufferedInputStream(new FileInputStream(filePath));
    PGPPublicKeyRingCollection pgpPublicKeyRingCollection = new PGPPublicKeyRingCollection(PGPUtil.getDecoderStream(inputStream), new JcaKeyFingerprintCalculator());
    Iterator keyRingIterator = pgpPublicKeyRingCollection.getKeyRings();
    while (keyRingIterator.hasNext()) {
        PGPPublicKeyRing keyRing = (PGPPublicKeyRing) keyRingIterator.next();
        Iterator keyIterator = keyRing.getPublicKeys();
        while (keyIterator.hasNext()) {
            PGPPublicKey key = (PGPPublicKey) keyIterator.next();
            if (key.isEncryptionKey()) {
                return key;
            }
        }
    }
    inputStream.close();
    throw new IllegalArgumentException("Can't find encryption key in key ring.");
}

private String getUserId(String publicKeyFile) throws IOException, PGPException {
    PGPPublicKey pgpPublicKey = getPGPPublicKey(publicKeyFile);
    // You can iterate and return all the user ids if needed
    return (String) pgpPublicKey.getUserIDs().next();
}