I get the error
java.sql.SQLException: JDBC4 Connection.isValid() method not supported, connection test query must be configured
This can be caused by two things: the first is an out of date Postgresql Driver. Make sure you are using version
42.2.1 or later.
Another cause is a malformed JDBC URL. HikiariCP, which throws this error, requires a URL in the format
jdbc:[vendor]://..... Make sure you are using the
JDBC_DATABASE_URL instead of