java - "must implement the inherited abstract method"

Question

我的类中有 AbstractJpaDao 方法

@Override
public EntityManager getEntityManager() {
    return em;
}

现在它不在使用中，我想删除它，但我收到错误:

类型JpaAclIdentityDao必须实现类JpaAclIdentityDao中继承的抽象方法IJpaDao.getEntityManager()。

那个 setter/getter 有必要吗？如果没有的话如何删除

我的代码:

public abstract class AbstractJpaDao implements IJpaDao {

protected final IApplicationConfig config;

protected final EntityManager em;

private final SingletonEventBus eventBus;

public AbstractJpaDao(EntityManager entityManager, IApplicationConfig config, SingletonEventBus eventBus) {
    checkArgument(entityManager != null);
    checkArgument(config != null);
    checkArgument(eventBus != null);
    this.em = entityManager;
    this.config = config;
    this.eventBus = eventBus;
}

protected void saveEntity(IEntity entity) {
    boolean isNew = entity.getId() == 0;
    em.getTransaction().begin();
    try {
        em.persist(entity);
        em.getTransaction().commit();
        if (isNew) {
            eventBus.post(new EntityCreatedEvent(entity));
        }
    } finally {
        if (em.getTransaction().isActive()) {
            em.getTransaction().rollback();
        }
    }
}



@Repository
public class JpaAclIdentityDao extends AbstractJpaDao implements IAclIdentityDao {



   public static final String GROUP_NAME_PATTERN = "GROUP_%d"; 

    private static final String GROUP_TEMP_NAME = "TEMP_GROUP_NAME"; 

@Inject
public JpaAclIdentityDao(EntityManager entityManager, IApplicationConfig config, SingletonEventBus eventBus) {
    super(entityManager, config, eventBus);
}

@Override
public AclIdentity findById(Object id) throws EntityNotFoundException {
    return em.find(AclIdentity.class, id);
}

@Override
public List<AclIdentity> findAll() {
    return findAllByType(AclIdentity.class);
}

@Override
public void delete(AclIdentity entity) {
    // TODO Auto-generated method stub
}

@Override
public void save(AclIdentity entity) {
    saveEntity(entity);
}

@Override
public AclIdentity createNew(String sid, boolean principal) {
    AclIdentity identity = new AclIdentity(sid, principal);
    save(identity);
    return identity;
}

@Override
public AclIdentity createNew(User entity) {
    return createNew(entity.getEmail(), true);
}

@Override
public AclIdentity createNew(Group entity) {
    AclIdentity identity = createNew(GROUP_TEMP_NAME, false);
    identity.setSid(String.format(GROUP_NAME_PATTERN, identity.getId()));
    save(identity);
    return identity;
}

}

Answer 1

是的，您必须实现已实现的接口(interface)中定义的所有方法。我能想到的唯一可能的解决方案是实现该方法并将其留空，或者不实现该接口(interface)。 或者，正如 ben75 所说，如果您不需要(任何地方)，只需删除接口(interface)“IJpaDao”声明中的方法即可。