java web application connect with Hana service through hdi container.

I just created a sap SDK web application that run on tomee7 container. next i tried to connect hana using hdi container. ( i referred https://help.sap.com/viewer/65de2977205c403bbc107264b8eccf4b/Cloud/en-US/7568c3d036f34a64bb6595b55805bffb.html#loiof0d2d059b43c48098772bd05d7c51d25 section : SAP HANA HDI Data Source Usage) i am getting data source but not getting connection , i am getting connection as null from datasource.
I have added ngdbc & sap cloud connecter dependency in pom.

any body has any sample code ? The same hdi instance i am able to connect with spring boot application in the same cloud foundry dev space. my POC is in https://github.com/kainattu/sap-sdk-cloud-db.git under main branch.

your help much appreciated!!. thanks in advance.