Spring如何正确注入集合类型

private Object resolveMultipleBeans(DependencyDescriptor descriptor, @Nullable String beanName,
      @Nullable Set<String> autowiredBeanNames, @Nullable TypeConverter typeConverter) {
   final Class<?> type = descriptor.getDependencyType();
   if (descriptor instanceof StreamDependencyDescriptor) {
      // 装配stream
      return stream;
   }
   else if (type.isArray()) {
      // 装配数组
      return result;
   }
   else if (Collection.class.isAssignableFrom(type) && type.isInterface()) {
      // 装配集合
      // 获取集合的元素类型
      Class<?> elementType = descriptor.getResolvableType().asCollection().resolveGeneric();
      if (elementType == null) {
         return null;
      }
      // 根据元素类型查找所有的bean
      Map<String, Object> matchingBeans = findAutowireCandidates(beanName, elementType,
            new MultiElementDescriptor(descriptor));
      if (matchingBeans.isEmpty()) {
         return null;
      }
      if (autowiredBeanNames != null) {
         autowiredBeanNames.addAll(matchingBeans.keySet());
      }
      // 转化查到的所有bean放置到集合并返回
      TypeConverter converter = (typeConverter != null ? typeConverter : getTypeConverter());
      Object result = converter.convertIfNecessary(matchingBeans.values(), type);
      // ...
      return result;
   }
   else if (Map.class == type) {
      // 解析map
      return matchingBeans;
   }
   else {
      return null;
   }
}