Java EE 将 Controller 类与 DAO 类连接

Question

我尝试将 Controller 连接到 DAO 类，但收到 UnsupportedOperationException。这是我的 Controller :

@Named("contactsController")
@SessionScoped

public class ContactsController implements Serializable {
    private static final long serialVersionUID = 1L;

    protected List<Contact> contacts;

    protected ContactsDAO contactsDAO = new ContactsDAOImp();

    @Inject
    public ContactsController(ContactsDAO contactsDAO) {
    this.contactsDAO = contactsDAO;
    }

    public List<Contact> getContacts() {
        return contacts;
    }

    @PostConstruct
    public void init() {
        this.contacts = contactsDAO.getAllContacts();
    }
}

这是我的 DAO:

@Named
@ApplicationScoped
public class ContactsDAOImp implements Serializable, ContactsDAO {
// DAO code here
}

错误:WELD-000049:无法在 com.controller.ContactsController@7e7514ca 上调用 public void com.controller.ContactsController.init()

似乎我未能将 DAO Referenec 注入(inject) Controller ，但我不确定我做错了什么

Answer 1

试试这个

@Named("contactsController")
@SessionScoped
public class ContactsController implements Serializable {

    private static final long serialVersionUID = 1L;
    private List<Contact> contacts;

    @Inject
    private ContactsDAOImp contactsDAOImp;

    public ContactsController() { }

    public List<Contact> getContacts() {
        return contacts;
    }

    @PostConstruct
    public void init() {
        this.contacts = contactsDAO.getAllContacts();
    }
}

ContactDAO(存储库？)

@Named
@ApplicationScoped
public class ContactsDAOImp implements Serializable, ContactsDAO {
    // DAO code here
}

编辑:您无法将存储库注入(inject)到 Controller 中，您应该在 Controller 和存储库之间放置一个层(服务)以在将数据发送到 View 之前操作数据