Android newest system version could not read .cer file public key

Question

I want get public key from .cer file, but failure. I find this error from Android newest system version, i can get public key in my lower Android system version.

String path = "/Users/mycompute/Projects/Test/src/workspace/mykeychain.cer";
CertificateFactory cf = CertificateFactory.getInstance("X.509");
FileInputStream in = new FileInputStream(path);
Certificate c = cf.generateCertificate(in);
PublicKey pubkey = c.getPublicKey();

in.close();

this code Certificate c = cf.generateCertificate(in); make error

error message:

java.io.IOException: Unknown named curve: 1.2.156.10197.1.301

what should i do?

i want get the file Hex public key.