是的，你可以像这样在UserRepresentation对象中添加属性：

@Autowired
private final Keycloak keycloak;

public void createUser(UserDTO userDTO){
UserRepresentation user = new UserRepresentation();
user.setUsername(userDTO.getUsername());
user.setEmail(userDTO.getEmailAddress());
user.setFirstName(userDTO.getFirstName());
user.setLastName(userDTO.getLastName());
RealmResource realmResource = keycloak.realm(REALM);
UsersResource userRessource = realmResource.users();
Map<String, List<String>> attr = new HashMap<>;// create your attr
user.setAttributes(attr);
// Create user
Response result = userRessource.create(user);
}