CDI injection with generic interfaces

Question

I have a problem with CDI injection. I want to build my DAO Layer with JPA and my Business Layer with EJB then using CDI to inject my DAO into Business Threat Logic.

For this, I define for my DAO layer One generic dao interface with contains CRUD methods and his generic dao implementation (an abstract class which implement a generic interface).

After, I define specific interfaces which implements Generic inteface and extends generic abstract class.

And I write a all of specifics dao.

In my Business Layer, I write a IGenericMetier interface which take back all CRUD methods, and a GenericMetier abstract class an implementation of IGenericMetier. Inside of GenericMetier, I inject a GenericDao interface to have access to all CRUD methods. For every entity I have Two (2) interfaces (Local and Remote) which extends IGenericMetier and a entity EJB Session which implement the two interfaces.

When I deploy the EAR project, there are many errors: org.jboss.weld.exceptions.DeploymentException: WELD-001409 Ambiguous dependencies for type ...

DAO Layer:

/** Generic methods for CRUD Operation **/
public interface IGenericDao<T extends GenericDto> {

    public T save(T obj) throws ExceptionDAO;
    public T consulter(Object id) throws ExceptionDAO;
    public T modifier(T obj) throws ExceptionDAO;
    public void supprimer(T obj) throws ExceptionDAO;
    public List<T> recupererTout() throws ExceptionDAO;
    public void flush();
}

Implementation of this interface

 /** Generic Implementation of this interfaces **/

    package com.omfd.dao.generic;

    import java.lang.reflect.ParameterizedType;
    import java.util.List;

    import javax.enterprise.inject.Default;
    import javax.persistence.EntityManager;
    import javax.persistence.PersistenceContext;

    import com.omfd.dao.exception.ExceptionDAO;
    import com.omfd.dto.core.GenericDto;

    public abstract class GenericDao<T extends GenericDto> implements IGenericDao<T> {
        @PersistenceContext
        private EntityManager em;

        protected Class<T> entityClass;

        @SuppressWarnings("unchecked")
        public GenericDao() {
            ParameterizedType genericSuperClass = (ParameterizedType)getClass().getGenericSuperclass();
            this.entityClass = (Class<T>)genericSuperClass.getActualTypeArguments()[0];
        }

        @Override
        public T save(T obj) throws ExceptionDAO {
            try {
                em.persist(obj);
                return obj;
            } catch (Exception e) {
                throw new ExceptionDAO("Une erreur est survenue");
            }

        }

        @Override
        public T consulter(Object id) throws ExceptionDAO {
            try {
                T entity = em.find(entityClass, id);
                return  entity;
            } catch (Exception ex) {
                throw new ExceptionDAO("Une erreur est survenue. Causse: "+ex.getCause());
            }

        }

        @Override
        public void supprimer(T obj) throws ExceptionDAO {
            obj = em.merge(obj);
            em.remove(obj);
        }

        @Override
        public T modifier(T obj) throws ExceptionDAO {
            try {
                T tModifie = em.merge(obj);
                return tModifie;
            } catch (Exception e) {
                throw new ExceptionDAO("Une erreur est survenue lors de la modification. Cause: "+e.getCause());
            }
        }

        @SuppressWarnings("unchecked")
        public List<T> recupererTout() throws ExceptionDAO {
            try {
                return em.createQuery("select obj from "+ entityClass.getSimpleName() +" obj").getResultList();
            } catch (Exception e) {
                throw new ExceptionDAO("Une erreur est survenue lors de la récupération des données.");
            }
        }

        @Override
        public void flush() {
            em.flush(); 
        }

    }

I have 12 Classes, but I'll give here two implementations

Specifics Interfaces:

package com.omfd.dao.interfaces;

import com.oci.omfd.entities.Direction;
import com.omfd.dao.generic.IGenericDao;

public interface IDirectionDao extends IGenericDao<Direction> {

}

package com.omfd.dao.interfaces;

import com.oci.omfd.entities.Roles;
import com.omfd.dao.generic.IGenericDao;

public interface IRolesDao extends IGenericDao<Roles> {

}

Specifics DAOs

package com.omfd.dao.impl;

import com.oci.omfd.entities.Direction;
import com.omfd.dao.exception.ExceptionDAO;
import com.omfd.dao.generic.GenericDao;
import com.omfd.dao.interfaces.IDirectionDao;

public class DirectionDao extends GenericDao<Direction> implements IDirectionDao {

}

package com.omfd.dao.impl;

import com.oci.omfd.entities.Roles;
import com.omfd.dao.generic.GenericDao;
import com.omfd.dao.interfaces.IRolesDao;

public class RolesDao extends GenericDao<Roles> implements IRolesDao{

}

Here you are The Business Layer Code

Generic interface for CRUD

public interface IGenericMetier<T extends GenericDto> {

    public T save(T obj) throws ExceptionBusiness;

    public T consulter(Object id) throws ExceptionBusiness;

    public T modifier(T obj) throws ExceptionBusiness;

    public void supprimer(T obj) throws ExceptionBusiness;

    public List<T> recupererTout() throws ExceptionBusiness;

    public void flush();
}

The implementation of this gneric interface Note: I injected the IGnericDao interface into this implementation

package com.omfd.metier.generic;

import java.util.List;

import javax.inject.Inject;

import com.omfd.dao.exception.ExceptionBusiness;
import com.omfd.dao.exception.ExceptionDAO;
import com.omfd.dao.generic.GenericDao;
import com.omfd.dao.generic.IGenericDao;
import com.omfd.dto.core.GenericDto;

public abstract class GenericMetier<T extends GenericDto> implements IGenericMetier<T> {

    @Inject
    private IGenericDao<T> dao;

    @Override
    public T save(T dir) throws ExceptionBusiness { 
        try {
            return dao.save(dir);
        } catch (ExceptionDAO e) {
            throw new ExceptionBusiness(e.getMessage());
        }
    }

    @Override
    public T consulter(Object id) throws ExceptionBusiness  {
        T entity = null;
        try {
            entity = dao.consulter(id);
        } catch (ExceptionDAO e) {
            throw new ExceptionBusiness(e.getMessage());
        }
        return entity;
    }


    @Override
    public void supprimer(T obj) throws ExceptionBusiness {
        try {
            dao.supprimer(obj);
        } catch (ExceptionDAO e) {
            throw new ExceptionBusiness(e.getMessage());
        }
    }

    @Override
    public T modifier(T obj) throws ExceptionBusiness {
        try {   
            return dao.modifier(obj);
        } catch (ExceptionDAO e) {
            throw new ExceptionBusiness(e.getMessage());
        }
    }


    public List<T> recupererTout() throws ExceptionBusiness{
        try {
            return dao.recupererTout();
        } catch (ExceptionDAO e) {
            throw new ExceptionBusiness(e.getMessage());
        }
    }

    @Override
    public void flush() {
        dao.flush();
    }

}

And I have Two Interfaces (local and remote) for each entity which extends IGenericMetier interface.

package com.omfd.metier.interfaces;
import javax.ejb.Local;

import com.oci.omfd.entities.Direction;
import com.omfd.metier.generic.IGenericMetier;

@Local
public interface IDirectionLocal extends IGenericMetier<Direction> {

}


package com.omfd.metier.interfaces;

import javax.ejb.Remote;

import com.oci.omfd.entities.Direction;
import com.omfd.metier.generic.IGenericMetier;

@Remote
public interface IDirectionRemote extends IGenericMetier<Direction> {
}

Roles Interfaces

package com.omfd.metier.interfaces;

import javax.ejb.Local;

import com.oci.omfd.entities.Roles;
import com.omfd.metier.generic.IGenericMetier;

@Local
public interface IRolesLocal extends IGenericMetier<Roles> {

}


package com.omfd.metier.interfaces;

import javax.ejb.Remote;

import com.oci.omfd.entities.Roles;
import com.omfd.metier.generic.IGenericMetier;

@Remote
public interface IRolesRemote extends IGenericMetier<Roles> {

}

To finish there implementations (Stateless EJB)

Direction Service ejb

package com.omfd.metier.impl;

import javax.ejb.Stateless;

import com.oci.omfd.entities.Direction;
import com.omfd.metier.generic.GenericMetier;
import com.omfd.metier.interfaces.IDirectionLocal;
import com.omfd.metier.interfaces.IDirectionRemote;

@Stateless(name="DS")
public class DirectionServices extends GenericMetier<Direction> implements IDirectionLocal, IDirectionRemote {

}

Roles Service EJB

package com.omfd.metier.impl;

import javax.ejb.Stateless;

import com.oci.omfd.entities.Roles;
import com.omfd.metier.generic.GenericMetier;
import com.omfd.metier.interfaces.IRolesLocal;
import com.omfd.metier.interfaces.IRolesRemote;

@Stateless(name="RS")
public class RolesServices extends GenericMetier<Roles> implements IRolesLocal, IRolesRemote {

}

Can someone helps me to fixe thes error ? When I deploy, I have these errors:

Exception 0 :
org.jboss.weld.exceptions.DeploymentException: WELD-001409 Ambiguous dependencies for type [IGenericDao<T>] with qualifiers [@Default] at injection point [[field] @Inject private com.omfd.metier.generic.GenericMetier.dao]. Possible dependencies [[Managed Bean [class com.omfd.dao.impl.NatureFraisDao] with qualifiers [@Any @Default], Managed Bean [class com.omfd.dao.impl.ServiceDao] with qualifiers [@Any @Default], Managed Bean [class com.omfd.dao.impl.OrdreMissionDao] with qualifiers [@Any @Default], Managed Bean [class com.omfd.dao.impl.CumulsDao] with qualifiers [@Any @Default], Managed Bean [class com.omfd.dao.impl.RolesDao] with qualifiers [@Any @Default], Managed Bean [class com.omfd.dao.impl.FraisDeplacement2Dao] with qualifiers [@Any @Default], Managed Bean [class com.omfd.dao.impl.FraisDeplacement1Dao] with qualifiers [@Any @Default], Managed Bean [class com.omfd.dao.impl.PersonnelDao] with qualifiers [@Any @Default], Managed Bean [class com.omfd.dao.impl.NouveauOrdreMissionDao] with qualifiers [@Any @Default], Managed Bean [class com.omfd.dao.impl.UserDao] with qualifiers [@Any @Default], Managed Bean [class com.omfd.dao.impl.DemandeOrdreMissionDao] with qualifiers [@Any @Default], Managed Bean [class com.omfd.dao.impl.DirectionDao] with qualifiers [@Any @Default]]]
    at org.jboss.weld.bootstrap.Validator.validateInjectionPoint(Validator.java:278)
    at org.jboss.weld.bootstrap.Validator.validateInjectionPoint(Validator.java:244)
    at org.jboss.weld.bootstrap.Validator.validateBean(Validator.java:107)
    at org.jboss.weld.bootstrap.Validator.validateRIBean(Validator.java:127)
    at org.jboss.weld.bootstrap.Validator.validateBeans(Validator.java:346)
    at org.jboss.weld.bootstrap.Validator.validateDeployment(Validator.java:331)
    at org.jboss.weld.bootstrap.WeldBootstrap.validateBeans(WeldBootstrap.java:366)
    at org.jboss.as.weld.WeldContainer.start(WeldContainer.java:83)
    at org.jboss.as.weld.services.WeldService.start(WeldService.java:76)
    at org.jboss.msc.service.ServiceControllerImpl$StartTask.startService(ServiceControllerImpl.java:1811)
    at org.jboss.msc.service.ServiceControllerImpl$StartTask.run(ServiceControllerImpl.java:1746)
    at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:885)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:907)
    at java.lang.Thread.run(Thread.java:619)

Exception 0 :
org.jboss.weld.exceptions.DeploymentException: WELD-001409 Ambiguous dependencies for type [IGenericDao<T>] with qualifiers [@Default] at injection point [[field] @Inject private com.omfd.metier.generic.GenericMetier.dao]. Possible dependencies [[Managed Bean [class com.omfd.dao.impl.NatureFraisDao] with qualifiers [@Any @Default], Managed Bean [class com.omfd.dao.impl.ServiceDao] with qualifiers [@Any @Default], Managed Bean [class com.omfd.dao.impl.OrdreMissionDao] with qualifiers [@Any @Default], Managed Bean [class com.omfd.dao.impl.CumulsDao] with qualifiers [@Any @Default], Managed Bean [class com.omfd.dao.impl.RolesDao] with qualifiers [@Any @Default], Managed Bean [class com.omfd.dao.impl.FraisDeplacement2Dao] with qualifiers [@Any @Default], Managed Bean [class com.omfd.dao.impl.FraisDeplacement1Dao] with qualifiers [@Any @Default], Managed Bean [class com.omfd.dao.impl.PersonnelDao] with qualifiers [@Any @Default], Managed Bean [class com.omfd.dao.impl.NouveauOrdreMissionDao] with qualifiers [@Any @Default], Managed Bean [class com.omfd.dao.impl.UserDao] with qualifiers [@Any @Default], Managed Bean [class com.omfd.dao.impl.DemandeOrdreMissionDao] with qualifiers [@Any @Default], Managed Bean [class com.omfd.dao.impl.DirectionDao] with qualifiers [@Any @Default]]]
    at org.jboss.weld.bootstrap.Validator.validateInjectionPoint(Validator.java:278)
    at org.jboss.weld.bootstrap.Validator.validateInjectionPoint(Validator.java:244)
    at org.jboss.weld.bootstrap.Validator.validateBean(Validator.java:107)
    at org.jboss.weld.bootstrap.Validator.validateRIBean(Validator.java:127)
    at org.jboss.weld.bootstrap.Validator.validateBeans(Validator.java:346)
    at org.jboss.weld.bootstrap.Validator.validateDeployment(Validator.java:331)
    at org.jboss.weld.bootstrap.WeldBootstrap.validateBeans(WeldBootstrap.java:366)
    at org.jboss.as.weld.WeldContainer.start(WeldContainer.java:83)
    at org.jboss.as.weld.services.WeldService.start(WeldService.java:76)
    at org.jboss.msc.service.ServiceControllerImpl$StartTask.startService(ServiceControllerImpl.java:1811)
    at org.jboss.msc.service.ServiceControllerImpl$StartTask.run(ServiceControllerImpl.java:1746)
    at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:885)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:907)
    at java.lang.Thread.run(Thread.java:619)

How can I fix this error ? Thank you for your answer

Answer 1

Most likely you run into this old bug: https://issues.jboss.org/browse/WELD-1111 This is fixed in Weld 1.1.8.Final and newer releases.