注入点带有限定符[@Default]的类型[...]的不满意依赖性（使用@Stateful EJB和CDI） [英] Unsatisfied dependencies for type [...] with qualifiers [@Default] at injection point (using @Stateful EJB with CDI)

问题描述

我有以下代码来管理两种存储库。这两个存储库类都继承一个接口，以允许对其资源进行重新初始化。

I have the following code to manage two kinds of repositories. Both repository classes inherit an interface to allow reinitialization of their resources.

public interface CachingRepository
{
    public void invalidateCache();
}

应用程序范围的全局回购：

Global, application-scoped repo:

@Named("globalRepo")
@ApplicationScoped
public class GlobalRepository implements CachingRepository
{
    private List<Category> categories;

    ...

    @Override
    public void invalidateCache()
    {
        categories = null;
    }

    ...
}

每个用户的会话范围的存储库：

Per user, session-scoped repo:

@Named("userRepo")
@SessionScoped
//@Stateful         // <- NOTE HERE
public class UserRepository implements CachingRepository, Serializable
{
    private List<MyFile> files;

    @Override
    public void invalidateCache()
    {
        files = null;
    }

    ...
}

将其（不带 @Stateful ）注入上下文时

When injecting this (without @Stateful) into the context

@Named
@ViewScoped
public class MyHandler implements Serializable
{
    @Inject
    private UserRepository userRepo;

    ...
}

它有效。但是，将 @Stateful 添加到 UserRepository 类时，部署失败，并显示以下异常：

it works. However, when adding @Stateful to the UserRepository class, deployment fails with an exception saying:

Caused by: org.jboss.weld.exceptions.DeploymentException: WELD-001408 Unsatisfied dependencies for type [UserRepository] with qualifiers [@Default] at injection point [[field] @Inject private de.company.project.pack.MyHandler.userRepo]
    at org.jboss.weld.bootstrap.Validator.validateInjectionPoint(Validator.java:275)
    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)
    ... 5 more

添加CDI bean的名称，例如

Adding the name of the CDI bean like

@Inject @Named("userRepo")
private UserRepository userRepo;

结果相同。与 @Stateful 一起使用的唯一方法是使用var声明中的接口：

results in the same exception. The only thing that works in conjunction with @Stateful is to use the interface in the var declaration:

@Inject @Named("userRepo")
private CachingRepository userRepo;

但是我可能在这里需要子类功能，所以使用 CachingRepository

I might need sub class functionality here however, so using CachingRepository isn't really desired (at the moment).

Q's ：

1. 为什么这不能正常工作？ UserRepository var应该已经标识了要实例化的类，不是吗？


2. 为什么 @Stateful EJB注释在这里产生如此严重的影响？为什么从本质上迫使我在var声明中使用 CachingRepository 接口？

1. Why isn't this working as expected? The UserRepository var should already identify which class to instantiate, shouldn't it? What's the logic to this?
2. Why does the @Stateful EJB annotation have such severe effects here? Why does it essentially force me into using the CachingRepository interface in the var declaration?

< hr>

注意，我使用Seam 3 Faces使 @ViewScoped 成为CDI视图，作用域Bean，因此当前的问题可能仍然是仅CDI 。

---

Note, I' using Seam 3 Faces making the @ViewScoped become a CDI view-scoped bean, so the problem at hand is likely still CDI-only.

推荐答案

与此误导性异常相同的问题...

I had the same problem with this misleading exception...

通过将 @Stateful 添加到 UserRepository ，您可以公开 CachingRepository 接口的EJB方法，而无需声明无接口视图。将 @LocalBean 添加到 UserRepository 以激活无接口视图。请参见EJB 3.1规范的第4.9.8节会话Bean的无接口视图

By adding @Stateful to UserRepository you expose EJB methods of the CachingRepository interface without having a no-interface view declared. Add @LocalBean to UserRepository to activate the no-interface view. See EJB 3.1 Specification, Section 4.9.8 "Session Bean's No-Interface View"

Bean类必须指定它公开了无-接口视图通过其bean类定义或在部署描述符中进行。适用以下规则：

The bean class must designate that it exposes a no-interface view via its bean class definition or in the deployment descriptor. The following rules apply:

• ...


• 如果bean暴露了至少一个其他客户端视图中，bean
  表示它通过bean类或部署
  描述符中的
  @LocalBean注释公开无接口视图。


• ...

我也指的是此stackoverflow 答案可提供有关无接口视图的更多信息。

I also refer to this stackoverflow answer for more information about no-interface views.

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