import java.io.File;
import java.io.FileInputStream;
import java.security.cert.CertificateFactory;
public class Main {
public static void main(String[] argv) throws Exception {
FileInputStream is = new FileInputStream(new File("your"));
CertificateFactory cf = CertificateFactory.getInstance("X.509");
java.security.cert.Certificate cert = cf.generateCertificate(is);
}
}