Returns true if this either implements the interface argument or is directly or indirectly a wrapper for an object that does.

  Returns true if this either implements the interface argument or is directly or indirectly a wrapper
for an object that does. Returns false otherwise. If this implements the interface then return true,
else if this is a wrapper then return the result of recursively calling isWrapperFor on the wrapped
object. If this does not implement the interface and is not a wrapper, return false.
This method should be implemented as a low-cost operation compared to unwrap so that
callers can use this method to avoid expensive unwrap calls that may fail. If this method
returns true then calling unwrap with the same argument should succeed.
Returns: true if this implements the interface or directly or indirectly wraps an object that does.
Parameters:
- iface - a Class defining an interface.
Throws:
- java.sql.SQLException - if an error occurs while determining whether this is a wrapper for an object with the given interface.
Since: 1.6

  Returns an object that implements the given interface to allow access to non-standard methods, or standard methods not exposed by the proxy.

  Returns an object that implements the given interface to allow access to
non-standard methods, or standard methods not exposed by the proxy.

If the receiver implements the interface then the result is the receiver
or a proxy for the receiver. If the receiver is a wrapper
and the wrapped object implements the interface then the result is the
wrapped object or a proxy for the wrapped object. Otherwise return the
the result of calling unwrap recursively on the wrapped object
or a proxy for that result. If the receiver is not a
wrapper and does not implement the interface, then an SQLException is thrown.
Returns: an object that implements the interface. May be a proxy for the actual implementing object.
Parameters:
- iface - A Class defining an interface that the result must implement.
Throws:
- java.sql.SQLException - If no object found that implements the interface
Since: 1.6