import java.io.FileInputStream;
import java.security.KeyStore;
import java.security.cert.Certificate;
public class MainClass {
public static void main(String[] args) throws Exception {
String keystoreFilename = "my.keystore";
char[] password = "password".toCharArray();
String alias = "alias";
FileInputStream fIn = new FileInputStream(keystoreFilename);
KeyStore keystore = KeyStore.getInstance("JKS");
keystore.load(fIn, password);
Certificate cert = keystore.getCertificate(alias);
System.out.println(cert);
}
}