java – 注入点的限定符[@Default]类型[…]的不满足依赖关系(使用带有CDI的@Stateful EJB)

我有以下代码来管理两种存储库.这两个存储库类都继承了一个接口,以便重新初始化其资源.

public interface CachingRepository
{
    public void invalidateCache();
}

全球应用范围的回购：

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

    ...

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

    ...
}

每个用户,会话范围的回购：

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

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

    ...
}

当注入(不用@Stateful)到上下文中

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

    ...
}

有用.但是,当将@Stateful添加到UserRepository类时,部署将失败,并显示以下异常：

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

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

导致同样的例外.与@Stateful一起工作的唯一的事情是在var声明中使用接口：

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

我可能需要子类功能,所以使用CachingRepository并不是真正需要的(目前).

Q记者：

>为什么这不按预期工作？ UserRepository var应该已经识别要实例化的类,不应该吗？这是什么逻辑？
>为什么@Stateful EJB注释在这里有如此严重的影响？为什么它基本上迫使我在var声明中使用CachingRepository接口？

注意,我使用Seam 3 Faces使@ViewScoped成为一个CDI视图范围的bean,所以手头的问题可能仍然是CDI.

解决方法

我有同样的问题,这个误导的例外…

通过将@Stateful添加到UserRepository,您将公开CachingRepository接口的EJB方法,而不声明无接口视图.将@LocalBean添加到UserRepository以激活无界面视图.参见EJB 3.1规范,第4.9.8节“会话Bean的无界面视图”

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:

• …
• If the bean exposes at least one other client view,the bean
  designates that it exposes a no-interface view by means of the
  @LocalBean annotation on the bean class or in the deployment
  descriptor.
• …

关于无界面视图的更多信息,我也参考this stackoverflow的答案.

原文地址：https://www.jb51.cc/java/126529.html