DataSourceHealthIndicator fails on Java 7+ and MySQL with "Conversion not supported for type java.lang.Object"

[wilkinsona]

This question on StackOverflow caused me to look into this. The failure is specific to Java 7 and later as ResultSet.getObject(index, type) is new in Java 7. The call to this method fails as the type that the health indicator passes in is java.lang.Object and MySQL's JDBC driver apparently doesn't know how to create one.

You could argue that by passing in java.lang.Object MySQL's JDBC driver should feel free to return whatever it wants rather than throwing an exception, but that's not the case and we should work around it if possible.

[wilkinsona]

Enabling auto-deserialization on the connection is one way to work around the problem:

spring.datasource.url: jdbc:mysql://localhost/test?autoDeserialize=true