If all the keys in a Map are values from a single enum, it is recommended to use an EnumMap as the specific
implementation. An EnumMap, which has the advantage of knowing all possible keys in advance, is more efficient compared to other
implementations, as it can use a simple array as its underlying data structure.
Noncompliant code example
public enum Color {
RED, GREEN, BLUE, ORANGE;
}
Map<Color, String> colorMap = new HashMap<>(); // Noncompliant
Compliant solution
public enum Color {
RED, GREEN, BLUE, ORANGE;
}
Map<Color, String> colorMap = new EnumMap<>(Color.class); // Compliant
