Is there any possibility to hide the "security warning message" via java coding?
No. If there was, it would be a bug. Depending on what warning is shown, it might be possible to stop it by digitally signing the code.
This answer describes one that cannot be changed.
This answer goes on to show how it looks when the certificate is generated by the developer.
Java has discovered application components that could indicate a security concern. Contact the application vendor to ensure that it has not been tampered with.
..but that is a mixed code warning produced by Java.