How to map domain object to Jpa entity using hexagonal architecture-CodePudding

after reading articles on hexagonal architecture, i decided to implement these practices. only i'm stuck in one place, i'd like to know how to map domain objects into domain entities. here is what i tried

//jpa entity

@Entity
@Data
public class Worker {
    @Id @GeneratedValue(strategy=GenerationType.IDENTITY)
    private Long id;
    private String phoneNumber;
    private String firstName;
    private String lastName;
    private String workerType;
    private String ifu;
    private String workerPicture;
    private String statut;
    
     @OneToMany(mappedBy = "worker")
      Set<CategoryWorker> category;
}

// domain model

public class Worker {
    private Long id;
    private String phoneNumber;
    private String firstName;
    private String lastName;
    private String workerType;
    private String ifu;
    private String imageParth;
    private String statut;
    }

// port out

public interface ListOfWorkerRepository {
    public List<Worker> findAll();
}

// port in

public interface ListOfWorker {
    public List<Worker> findAll();
}

// adapters out

public class ListWorkerImpl implements ListOfWorkerRepository{
    WorkerJpaInterface workerJpaInterface;
    @Override
    
    public List<Worker> findAll() {
        
        return  workerJpaInterface.findAll();
    }

}
// here I have an conversion error

CodePudding user response：

I guess it's because both of classes are called 'Worker'. If you rename it to 'WorkerJpa' and 'WorkerDomain' you will find what's wrong. I said 'I guess' cause we don't see stack trace and package structures what would help to analyze. You need a kind of an WorkerMapper (sth like entity to Dto mapper, java class or using MapStruct, etc.). Usually it should be in WorkerJpa package as we assume that external Worker class structure can change and should be adjusted by mapper to Domain entity.

CodePudding user response：

Here:

public List<Worker> findAll() {
    return  workerJpaInterface.findAll();
}

You will have a conversion error because they're different classes as crush84 correctly pointed out. I think you need to go through the jpa Worker and create a new domain model Worker for each one.

public List<Worker> findAll() {
    List<Worker> jpaWorkers = workerJpaInterface.findAll(); 
    List<Worker> domWorkers = new ArrayList<>();
    // your IDE should scream at you here about different Worker classes
    // so you would have to specify explicitly which worker you're talking about
    for(Worker jpaWorker : jpaWorkers) {
        Worker domWorker = new Worker();
        domWorker.setPhoneNumber(jpaWorker.getPhoneNumber());
        domWorker.setName(jpaWorker.getName());
        //set all the properties of domain model worker 
        //using values from jpa worker
}

Be very careful about imports and usage of Worker - you don't want to mix them up. Maybe you could rename them to be something more descriptive to avoid confusion in the future? I hope this helps :D