Currently, we are using:

"com.zaxxer:HikariCP-java6:2.3.9"

This is a Java 1.6 dependency which does not implement on top of JDBC 4.1 (Java 1.7) and JDBC 4.2 (Java 1.8).

Since Hibernate ORM 5.2 already uses Java 1.8, it's time to upgrade to the default HikariCP version which is based on Java 1.8:

"com.zaxxer:HikariCP:2.5.1"