如何從父類路徑使用CDI託管bean

Question

我正在開發一個CDI庫。這工作正常。但是當我嘗試在項目中使用這個庫作爲包含的Jar時，CDI抱怨說它無法解決在父項目中定義的託管Bean的依賴關係。

MyProject的 - MyLib.jar - MyManagedBean

所以MyLib中需要注入與刻板印象@foo註解的bean。這種刻板印象應用於MyManagedBean。

@foo 
public class MyManagedBean { 
    //... 
} 

我也將beans.xml添加到了我的父項目中。但它就像有兩個不同的CDI容器，MyLib無法訪問MyProject。

有什麼建議嗎？

Answer 1

我能夠通過使用CDI擴展來訪問父類文件。 Documentation和反思。

這是我使用的代碼：

public class ConfigExtension implements Extension { 

void afterBeanDiscovery(@Observes AfterBeanDiscovery abd, BeanManager bm) { 
    Reflections reflections = new Reflections(""); 
    Set<Class<?>> types = reflections.getTypesAnnotatedWith(Tester.class); 
    types.remove(info.scandi.fusion.cucumber.Tester.class); 
    types.addAll(reflections.getTypesAnnotatedWith(Driver.class)); 
    types.addAll(reflections.getTypesAnnotatedWith(Worker.class)); 

    types.forEach(type -> { 
     abd.addBean(new FusionBean((Class<T>) type, bm)); 
    }); 
} 

} 

public class FusionBean<T> implements Bean<T>, Serializable, PassivationCapable { 

/** 
* 
*/ 
private static final long serialVersionUID = 1L; 
private InjectionTarget<T> it; 
private Class<T> bean; 
private BeanManager bm; 

public FusionBean(Class<T> workerClass, BeanManager bm) { 
    this.bm = bm; 
    bean = workerClass; 
    AnnotatedType<T> at = bm.createAnnotatedType(bean); 
    // use this to instantiate the class and inject dependencies 
    it = bm.createInjectionTarget(at); 
} 

@Override 
public T create(CreationalContext<T> creationalContext) { 
    T instance = it.produce(creationalContext); 
    it.inject(instance, creationalContext); 
    it.postConstruct(instance); 
    return instance; 
} 

@Override 
public void destroy(T instance, CreationalContext<T> creationalContext) { 
    it.preDestroy(instance); 
    it.dispose(instance); 
    creationalContext.release(); 
} 

@Override 
public Set<Type> getTypes() { 
    Set<Type> types = new HashSet<>(); 
    //Use Apache Common Lang to get all Interfaces and Superclasses 
    types.addAll(ClassUtils.getAllInterfaces(bean)); 
    types.addAll(ClassUtils.getAllSuperclasses(bean)); 
    return types; 
} 

@Override 
public Set<Annotation> getQualifiers() { 
    Set<Annotation> annotations = new HashSet<>(); 
    for (int i = 0; i < bean.getAnnotations().length; i++) { 
     Class<? extends Annotation> possibleQualifier = bean.getAnnotations()[i].annotationType(); 
     if (bm.isQualifier(possibleQualifier)) { 
      annotations.add(bean.getAnnotations()[i]); 
     } 
    } 
    return annotations; 
} 

@Override 
public Class<? extends Annotation> getScope() { 
    for (int i = 0; i < bean.getAnnotations().length; i++) { 
     Class<? extends Annotation> possibleScope = bean.getAnnotations()[i].annotationType(); 
     if (bm.isStereotype(possibleScope)) { 
      for (Annotation annotation : possibleScope.getAnnotations()) { 
       if (bm.isScope(annotation.annotationType())) { 
        return annotation.annotationType(); 
       } 
      } 
     } 
    } 
    return null; 
} 

@Override 
public String getName() { 
    return bean.getName(); 
} 

@Override 
public Set<Class<? extends Annotation>> getStereotypes() { 
    Set<Class<? extends Annotation>> stereotypes = new HashSet<>(); 
    for (int i = 0; i < bean.getAnnotations().length; i++) { 
     Class<? extends Annotation> possibleStereotype = bean.getAnnotations()[i].annotationType(); 
     if (bm.isStereotype(possibleStereotype)) { 
      stereotypes.add(possibleStereotype); 
     } 
    } 
    return stereotypes; 
} 

@Override 
public boolean isAlternative() { 
    for (int i = 0; i < bean.getAnnotations().length; i++) { 
     if (bean.getAnnotations()[i].equals(Alternative.class)) { 
      return true; 
     } 
    } 
    return false; 
} 

@Override 
public Class<?> getBeanClass() { 
    return bean.getClass(); 
} 

@Override 
public Set<InjectionPoint> getInjectionPoints() { 
    return it.getInjectionPoints(); 
} 

@Override 
public boolean isNullable() { 
    return false; 
} 

@Override 
public String getId() { 
    return UUID.randomUUID().toString(); 
} 

} 

訣竅是CDI擴展訪問父類路徑。在這裏，我使用Reflection api來獲取使用我的框架的用戶可以指定的Tester，Driver et Worker類。