You are supposed to use generics: Iterator<Map.Entry<UUID, ExpiringEntityPlayer>> ghostI = hashtableNPCs.entrySet().iterator(); while (ghostI.hasNext()

You are supposed to use generics: Iterator<Map.Entry<UUID, ExpiringEntityPlayer>> ghostI = hashtableNPCs.entrySet().iterator(); while (ghostI.hasNext()) { ExpiringEntityPlayer expiringEntityPlayer = ghostI.next().getValue(); } However, it's a sham. The generic types are stripped at runtime. The compiler will prevent you from putting values in the map that are not an ExpiringEntityPlayer, as long as you are diligent in using generics everywhere, and don't fall in the few traps where the wrong type can slip by without a warning, but you can still be hit by a ClassCastException at runtime if you're not careful.