An inherited member type shadows a single-type import of the same name

Fact

In Java, a member type inherited from a superclass or an implemented interface takes precedence over a single-type import with the same simple name. A class that implements Renderer, where Renderer declares a nested Format, resolves every bare Format inside that class to Renderer.Format — even with import com.example.util.Format; at the top of the file.

Why it matters

The failure looks nothing like a name clash. The compiler reports cannot find symbol: method timestamp(Instant) on the imported class's own methods, because it is looking them up on the inherited nested type instead. The import sits there unused and blameless, and only the classes that implement the interface are affected — its siblings compile fine, which points suspicion at the utility class rather than at the interface.

How to apply

• Do not give a nested type in an interface a name that a widely imported class already uses. Enum names like Format, Type, Kind, State and Entry are the usual collisions.
• Prefer a top-level enum to a nested one when the interface has many implementors and the name is generic.
• When the error insists a method is missing from a class you can see declaring it, print the resolved type: Format.class.getName() names the winner immediately, and a fully qualified reference confirms the diagnosis.