Use static factory methods for wrapper types

[marschall]

The driver currently instantiates wrapper types (Integer, Long, …) by directly calling the constructor using new rather than by calling the static valueOf factory methods. This is discouraged and deprecated in Java 9. To quote from the Integer constructor

It is rarely appropriate to use this constructor. The static factory valueOf(int) is generally a better choice, as it is likely to yield significantly better space and time performance.

[ajlam]

Filing as follow-up for JDK9.

[marschall]

This is not really a JDK9 issue. Is this more a performance issue as the status valueOf methods reduce pressure on both the allocator and the heap.

[ajlam]

@marschall - Understood. The tag is for following up when we schedule our work for JDK9 support.

[xiangyushawn]

Thank you @marschall. I’m closing this issue since the PR has been merged.