当前位置：首页 > news >正文

巧用@Conditional注解根据配置文件注入不同的bean对象

news 2025/8/18 10:28:02

项目中使用了mq，kafka两种消息队列进行发送数据，为了避免硬编码，在项目中通过不同的配置文件自动识别具体消息队列策略。这里整理两种实施方案，仅供参考！

方案一：创建一个工具类，然后根据配置文件来返回具体的IBase实现类

1.IBaseService

/*** 发送数据接口*/
public interface IBaseService {void send();
}

2.KafkaServiceImpl

@Service
public class KafkaServiceImpl implements IBaseService {@AutowiredMyConfiguration myConfiguration;@Overridepublic void send() {System.out.println("调用Kafka接口发送数据！");myConfiguration.init("-------------Kafka-------------");}
}

3.MQServiceImpl

@Service
public class MQServiceImpl implements IBaseService {@AutowiredMyConfiguration myConfiguration;@Overridepublic void send() {System.out.println("调用MQ接口，发送数据！");myConfiguration.init("-------------MQ-----------");}
}

4.SendMessageUtil

/*** 根据不同配置文件，选择发送消息工具类*/
@Component
public class SendMessageUtil {//message.type在application.yaml，":kafka" 设置默认值为kafka@Value("${message.type:kafka}")private String type;@AutowiredKafkaServiceImpl kafkaService;@AutowiredMQServiceImpl mqService;public IBaseService get(){if (type.equals("kafka"))return kafkaService;elsereturn mqService;}
}

5.方案一单元测试及测试结果

application.yaml

message:type: kafka

	@AutowiredSendMessageUtil sendMessageUtil;@Testvoid contextLoadsTwo() {IBaseService tempBaseService = sendMessageUtil.get();tempBaseService.send();}

请添加图片描述

方案二：@Conditional注解根据配置文件注入不同的bean对象

1.KafkaCondition

/*** Kafka推送方式*/
public class KafkaCondition implements Condition {@Overridepublic boolean matches(ConditionContext context, AnnotatedTypeMetadata metadata) {Environment environment = context.getEnvironment();String type = environment.getProperty("message.type");if (type.contains("kafka")){return true;}return false;}
}

2.KafkaServiceImpl上面加上@Conditional(KafkaCondition.class)

3.MQCondition

/*** MQ推送方式*/
public class MQCondition implements Condition {@Overridepublic boolean matches(ConditionContext context, AnnotatedTypeMetadata metadata) {Environment environment = context.getEnvironment();String type = environment.getProperty("message.type");if (type.contains("mq")){return true;}return false;}
}

4.MQServiceImpl上面加上@Conditional(MQCondition.class)

5.方案二单元测试及测试结果

application.yaml

message:type: kafka

// 注意:运行contextLoadsTwo测试方法时候，需要将iBaseService全部注释掉，否则会报错// 也要将KafkaServiceImpl和MQServiceImpl上面@Conditional注释掉@AutowiredSendMessageUtil sendMessageUtil;@Testvoid contextLoadsTwo() {IBaseService tempBaseService = sendMessageUtil.get();tempBaseService.send();}