spring如何优雅处理策略模式if类型判断

@Service
public class B1Impl implements InterfaceB {
    //通过map key放类型，值放抽象类型，每次就不用if判断了
    Map<String, InterfaceA> interfaceAMap = new HashMap<>();

    //spring 会自动注入interfaceA的所有实现
    @Bean("testB1Impl")
    public Map<String, InterfaceA> B1Impl(List<InterfaceA> interfaceA) {

        if(CollectionUtils.isEmpty(interfaceA)) {
            return null;
        }

        for(InterfaceA a : interfaceA){
            interfaceAMap.put(a.getType(),a);
        }

        return interfaceAMap;
    }


    @Override
    public Map<String, InterfaceA> getInterfaceAMap() {
        return interfaceAMap;
    }
}