You could also do something as follow
public enum DAY {MON, TUES, WED, THU, FRI, SAT, SUN};
EnumSet.allOf(DAY.class).stream().map(e -> e.name()).collect(Collectors.toList())
or
EnumSet.allOf(DAY.class).stream().map(DAY::name).collect(Collectors.toList())
The main reason why I stumbled across this question is that I wanted to write a generic validator that validates whether a given string enum name is valid for a given enum type (Sharing in case anyone finds useful).
For the validation, I had to use Apache's EnumUtils library since the type of enum is not known at compile time.
@SuppressWarnings({ "unchecked", "rawtypes" })
public static void isValidEnumsValid(Class clazz, Set<String> enumNames) {
Set<String> notAllowedNames = enumNames.stream()
.filter(enumName -> !EnumUtils.isValidEnum(clazz, enumName))
.collect(Collectors.toSet());
if (notAllowedNames.size() > 0) {
String validEnumNames = (String) EnumUtils.getEnumMap(clazz).keySet().stream()
.collect(Collectors.joining(", "));
throw new IllegalArgumentException("The requested values '" + notAllowedNames.stream()
.collect(Collectors.joining(",")) + "' are not valid. Please select one more (case-sensitive) "
+ "of the following : " + validEnumNames);
}
}
I was too lazy to write an enum annotation validator as shown in here https://stackoverflow.com/a/51109419/1225551