I am trying to write a DAO interface using Datastax 4.2.2, but getting several compile errors

I have the following POJO:

@Table(name = "order", readConsistency = "QUORUM", writeConsistency = "QUORUM")
public class Order {    
    
    @Column(name = "id")
    @PartitionKey
    private String id;

    @Column(name = "customer_id")
    private String customerId;

    @Column(name = "loyalty_id")
    private String loyaltyId;

    @Column(name = "customer_email")
    private String customerEmail;

    public Order() {

    }
    ... getters and setters
}

And now I am writing the OrderDao as following:

	import com.datastax.oss.driver.api.mapper.annotations.*;

	@Dao
	public interface OrderDao {
		    @Select
		    Order findById(String orderId);

		    @Insert
		    void save(Order order);

		    @Delete
		    void delete(Order order);
	}

And when I do ./gradlew build I get the following errors:

error: Invalid return type: Select methods must return one of [ENTITY, OPTIONAL_ENTITY, FUTURE_OF_ENTITY, FUTURE_OF_OPTIONAL_ENTITY, PAGING_ITERABLE, FUTURE_OF_ASYNC_PAGING_ITERABLE]
    Order findById(String orderId);

error: Insert methods must take the entity to insert as the first parameter
    void save(Order order);
         ^

error: Missing entity class: Delete methods that do not operate on an entity instance must have an 'entityClass' argument
    void delete(Order order);
         ^

I am implementing by following the documentation here: https://docs.datastax.com/en/developer/java-driver/4.2/manual/mapper/ . What could be the possible cause of this?

Thanks.

You are missing the @Entity annotation on your Order class:

@Entity
@Table(name = "order", readConsistency = "QUORUM", writeConsistency = "QUORUM")
public class Order {