RSA根据modulus,exponent生成公钥

// 根据n、e值还原公钥

 public static PublicKey getPublicKey(String modulus, String publicExponent)            throws NoSuchAlgorithmException, InvalidKeySpecException {        BigInteger bigIntModulus = new BigInteger(modulus,16);        BigInteger bigIntPrivateExponent = new BigInteger(publicExponent,16);        RSAPublicKeySpec keySpec = new RSAPublicKeySpec(bigIntModulus, bigIntPrivateExponent);        KeyFactory keyFactory = KeyFactory.getInstance("RSA");        PublicKey publicKey = keyFactory.generatePublic(keySpec);        return publicKey;    }