// enums/EnumMaps.java

// (c)2017 MindView LLC: see Copyright.txt

// We make no guarantees that this code is fit for any purpose.

// Visit http://OnJava8.com for more book information.

// Basics of EnumMaps

// {java enums.EnumMaps}

package enums;

import java.util.*;

import static enums.AlarmPoints.*;

interface Command { void action(); }

public class EnumMaps {

public static void main(String[] args) {

EnumMap<AlarmPoints,Command> em =

new EnumMap<>(AlarmPoints.class);

em.put(KITCHEN,

() -> System.out.println("Kitchen fire!"));

em.put(BATHROOM,

() -> System.out.println("Bathroom alert!"));

for(Map.Entry<AlarmPoints,Command> e:

em.entrySet()) {

System.out.print(e.getKey() + ": ");

e.getValue().action();

}

try { // If there's no value for a particular key:

em.get(UTILITY).action();

} catch(Exception e) {

System.out.println("Expected: " + e);

}

}

}

/* Output:

BATHROOM: Bathroom alert!

KITCHEN: Kitchen fire!

Expected: java.lang.NullPointerException

*/