//: enumerated/EnumMaps.java // Basics of EnumMaps. package enumerated; import java.util.*; import static enumerated.AlarmPoints.*; import static net.mindview.util.Print.*; interface Command { void action(); } public class EnumMaps { public static void main(String[] args) { EnumMap em = new EnumMap<>(AlarmPoints.class); em.put(KITCHEN, () -> print("Kitchen fire!")); em.put(BATHROOM, () -> print("Bathroom alert!")); for(Map.Entry e : em.entrySet()) { printnb(e.getKey() + ": "); e.getValue().action(); } try { // If there's no value for a particular key: em.get(UTILITY).action(); } catch(Exception e) { print("Expected: " + e); } } } /* Output: BATHROOM: Bathroom alert! KITCHEN: Kitchen fire! Expected: java.lang.NullPointerException *///:~