How to map multiple enums to string (and back) using their common property with MapStruct?
I have two enums with common property - id:
public enum AccessLevel {
PUBLIC("public"),PRIVATE("private");
private String id;
}
public enum Status {
SUCCESS("success"),TIMEOUT("timeout");
private String id;
}
And I need generic MapStruct mapping of such enums (without need to define mapping of every such enum).
Solution 1:
Yes, it's possible through @TargetType annotation. You need a common interface for such enums:
public interface IdEnum {
String getId();
}
Then you need to be able to create enum of such interface instance by id:
static <T extends Enum<T> & IdEnum> T getById(Class<T> enumClass, String id) {
for (T e : enumClass.getEnumConstants()) {
if (e.getId().equals(id)) {
return e;
}
}
throw new IllegalArgumentException("No enum const " + enumClass.getName() + " for id '" + id + "'");
}
Then the generic Mapper may look like this (@TargetType annotation is the key to success):
public class IdEnumMapper {
public <T extends Enum<T> & IdEnum> T mapToEnum(String value, @TargetType Class<T> idEnumClass) {
return IdEnum.getById(idEnumClass, value);
}
public String mapToString(IdEnum idEnum) {
return idEnum.getId();
}
}
Just use it your mapper that maps a class that contains such enums:
@Mapper(uses = {IdEnumMapper.class})
public interface FilterMapper {
....