java - 多种类型的相同接口(interface)

Question

我有一个接口(interface)，并且有一些实现。每个实现都属于某种类型。我希望当我使用 Autowiring 时，我能够获得特定类型的所有实现。我该怎么做？

public interface someInterface{}

public class impl1OfType1 implements someInterface{}
public class impl2OfType1 implements someInterface{}

public class impl1OfType2 implements someInterface{}
public class impl2OfType2 implements someInterface{}

public class someClass{
   @autowired
   public someClass(List<someInterface> interfaceList){}

}

我只想获取 impl1OfType1 和 impl2OfType1。而且不是全部实现。在其他地方，我只想获取 impl1OfType2 和 impl2OfType2。

更具体的例子 -

    public interface EntityCreator{
      createEntity();
    }

    @Component
    public class DogCreator implements entityCreator{}
    @Component
    public class CatCreator implements entityCreator{}
    @Component
    public class CarCreator implements entityCreator{}
    @Component
    public class TruckCreator implements entityCreator{}

    @Component
    public class AnimalsFactory{
       @Autowired
       public AnimalsFactory(List<EntityCreator> creators){}

    }

Answer 1

解决方案是使用 @Qualifier .

@Component
@Qualifier("place1")
class Impl1OfType2 implements SomeInterface {}

@Component
@Qualifier("place1")
class Impl2OfType2 implements SomeInterface {}

@Service
class SomeClass {
    @Autowired
    public SomeClass(@Qualifier("place1") List<SomeInterface> interfaceList) {
        System.out.println(interfaceList);
    }
}

我稍微更改了名称以遵守 Java 约定。他们仍然有点尴尬和没有背景。

更新

你可能会使用泛型，Spring 擅长处理它们。例如，它只会注入(inject) DogCreator和CatCreator进入List<EntityCreator<Animal>> .

interface Animal {}
interface Machine {}

interface EntityCreator<T> {}

@Component
class DogCreator implements EntityCreator<Animal> {}
@Component
class CatCreator implements EntityCreator<Animal> {}

@Component
class CarCreator implements EntityCreator<Machine> {}
@Component
class TruckCreator implements EntityCreator<Machine> {}

@Component
class AnimalsFactory {
    @Autowired
    public AnimalsFactory(List<EntityCreator<Animal>> creators) { }
}

更新2

您可以编写标记接口(interface)，将现有实现分解为逻辑组。

interface AnimalCreator {}

interface EntityCreator<T> {}

@Component
class DogCreator implements EntityCreator, AnimalCreator {}
@Component
class CatCreator implements EntityCreator, AnimalCreator {}

@Component
class AnimalsFactory {
    @Autowired
    public AnimalsFactory(List<AnimalCreator> creators) {
        System.out.println(creators);
    }

}