一个接口多个实现类，如何调用哪个实现类的方法

springboot项目中通过applicationContext.getBeansOfType(class)获取某一接口的所有实现类，并通过枚举完成策略模式，替代if/else,使代码更加优雅易于扩展

@Component
public class MqttSubscribeAdapter implements ApplicationContextAware {

    /**
     * mqtt订阅消息处理实现类实例
     */
    private static Map<MqttSubTopicEnum, MqttSubscribeHandlerService> handlerServiceMap;

    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        Map<String, MqttSubscribeHandlerService> map = applicationContext.getBeansOfType(MqttSubscribeHandlerService.class);
        handlerServiceMap = new HashMap<>(map.size());
        map.forEach((key, value) ->
                handlerServiceMap.put(value.obtainSubscribedTopic(), value)
        );
    }

    /***
     * @Description 获取处理的service
     * @Param actionType
     * @Return T
     * @Author xzq
     * @Date 2020/10/21
     */
    public static <T extends MqttSubscribeHandlerService> T obtainProcessService(MqttSubTopicEnum topicEnum) {
        return (T)handlerServiceMap.get(topicEnum);
    }
}

/***
 * @Description 分发处理订阅消息
 * @Param topic
 * @Param payload
 * @Return void
 * @Author xzq
 * @Date 2020/11/4
 */
public void dispatch(String topic, String payload){
    MqttSubTopicEnum mqttSubTopicEnum = topicMatching(topic);
    if(mqttSubTopicEnum == null){
        log.error("订阅消息分发处理异常，无效的topic:{}", topic);
        return;
    }
    MqttSubscribeHandlerService mqttSubscribeHandlerService = MqttSubscribeAdapter.obtainProcessService(mqttSubTopicEnum);
    if(null == mqttSubscribeHandlerService){
        log.error("订阅消息分发处理异常，topic无对应的处理逻辑:{}", topic);
        return;
    }

    // 订阅处理
    mqttSubscribeHandlerService.subscribeHandler(topic, payload);
}

/***
 * @Description 处理增强匹配
 * @Param topic
 * @Return com.wave.kit.device.mqtt.MqttSubscribeHandlerService
 * @Author xzq
 * @Date 2020/12/26
 */
private MqttSubTopicEnum topicMatching(String topic){
    for (MqttSubTopicEnum typeEnum : MqttSubTopicEnum.values()) {
        if (isMatch(topic, typeEnum.getTopic())) {
            return typeEnum;
        }
    }
    return null;
}