如何在java中将十六进制字符串转换为公钥？(java.security.InvalidKeyException)

public static byte[] hexStringToByteArray(String hexString) {
    int len = hexString.length();
    byte[] byteArray = new byte[len / 2];
    for (int i = 0; i < len; i += 2) {
        byteArray[i / 2] = (byte) ((Character.digit(hexString.charAt(i), 16) << 4)
                             + Character.digit(hexString.charAt(i + 1), 16));
    }
    return byteArray;
}

import java.security.KeyFactory;
import java.security.PublicKey;
import java.security.spec.X509EncodedKeySpec;

public static PublicKey getPublicKeyFromHexString(String hexString) throws Exception {
    byte[] publicKeyBytes = hexStringToByteArray(hexString);
    X509EncodedKeySpec keySpec = new X509EncodedKeySpec(publicKeyBytes);
    KeyFactory keyFactory = KeyFactory.getInstance("RSA"); // 这里假设使用RSA算法
    PublicKey publicKey = keyFactory.generatePublic(keySpec);
    return publicKey;
}

import java.security.KeyFactory;
import java.security.PublicKey;
import java.security.spec.X509EncodedKeySpec;

public class Main {
    public static void main(String[] args) {
        String hexString = "0123456789ABCDEF"; // 十六进制字符串
        try {
            PublicKey publicKey = getPublicKeyFromHexString(hexString);
            System.out.println("公钥：" + publicKey);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public static byte[] hexStringToByteArray(String hexString) {
        int len = hexString.length();
        byte[] byteArray = new byte[len / 2];
        for (int i = 0; i < len; i += 2) {
            byteArray[i / 2] = (byte) ((Character.digit(hexString.charAt(i), 16) << 4)
                    + Character.digit(hexString.charAt(i + 1), 16));
        }
        return byteArray;
    }

    public static PublicKey getPublicKeyFromHexString(String hexString) throws Exception {
        byte[] publicKeyBytes = hexStringToByteArray(hexString);
        X509EncodedKeySpec keySpec = new X509EncodedKeySpec(publicKeyBytes);
        KeyFactory keyFactory = KeyFactory.getInstance("RSA"); // 这里假设使用RSA算法
        PublicKey publicKey = keyFactory.generatePublic(keySpec);
        return publicKey;
    }
}