package chapter19._9;
import chapter19._8.AlarmPoints;
import java.util.EnumMap;
import java.util.Map;
import static chapter19._8.AlarmPoints.*;
interface Command {
void action();
}
public class EnumMaps {
public static void main(String[] args) {
EnumMap<AlarmPoints, Command> em = new EnumMap<AlarmPoints, Command>(AlarmPoints.class);
em.put(KITCHEN, new Command() {
@Override
public void action() {
System.out.println("Kitchen fire!");
}
});
em.put(BATHROOM, new Command() {
@Override
public void action() {
System.out.println("Bathroom alert!");
}
});
for (Map.Entry<AlarmPoints, Command> e : em.entrySet()) {
System.out.print(e.getKey() + ": ");
e.getValue().action();
}
try {
em.get(UTILITY).action();
} catch (Exception e) {
System.out.println(e);
}
}
}
输出：
BATHROOM: Bathroom alert!
KITCHEN: Kitchen fire!
java.lang.NullPointerException
