import java.io.FileInputStream;
import java.security.KeyStore;
import java.security.cert.CertPath;
import java.security.cert.Certificate;
import java.security.cert.CertificateFactory;
import java.util.Arrays;
public class Main {
public static void main(String[] argv) throws Exception {
FileInputStream is = new FileInputStream("your.keystore");
KeyStore keystore = KeyStore.getInstance(KeyStore.getDefaultType());
keystore.load(is, "my-keystore-password".toCharArray());
String alias = "myalias";
Certificate cert = keystore.getCertificate(alias);
CertificateFactory certFact = CertificateFactory.getInstance("X.509");
CertPath path = certFact.generateCertPath(Arrays.asList(new Certificate[]{cert}));
}
}