Autowiring a DAO into a domain object

Question

I am coding a ribbon/achievements system for a website and I have to write some logic for each ribbon in my system. For example, you could earn a ribbon if you're in the first 2,000 people registering to the website or after 1,000 post in the forum. The idea is very similar to stackoverflow's badges, really. So, every ribbon is obviously in the database but they also need a bit of logic to determine when a user has earned the ribbon. In the way I coded it, `Ribbon` is a simple abstract class: ``` @Entity @Table(name = "ribbon") @Inheritance(strategy = InheritanceType.SINGLE_TABLE) @DiscriminatorColumn(name = "ribbon_type") public abstract class Ribbon { @Id @Column(name = "id", nullable = false, length = 8) private int id; @Column(name = "title", nullable = false, length = 64) private String title; public Ribbon() { } public abstract boolean isEarned(User user); // ... getters/setters... } ``` You can see I define the inheritance strategy as `SINGLE_TABLE` (since I have to code like 5…

Accepted Answer

I'm not saying that I agree with injecting DAOs into domain instances....but

You can wire your DAO into you domain object. But you'll have to declare your domain object in your spring application-context and obtain new instances from Spring NOT using `new`. Make sure that you use the prototype scope! You don't want to be getting the same singleton instance everytime!

Really this logic that you want to implement belongs in a service which is injected with the DAOs that it requires.

Perhaps you could have a service like:

```
@Service
public class RibbonServiceImpl implements RibbonService

@Autowired
  private RibbonDAO ribbonDAO;

public boolean isEarned(Ribbon ribbon, User user) {
   if(!userHasRibbonDao.userHasRibbon(user, this))
        {
            // TODO
            // All the logic to determine whether the user earned the ribbon
            // i.e. check whether the user is between the first 2000 users who registered to the website
            // Other autowired DAOs are needed
        }
        else
        {
            return true;
        }

return false;
  }  
```

Autowiring a DAO into a domain object

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