巧用@Conditional注解根据配置文件注入不同的bean对象

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 {
    @Autowired
    MyConfiguration myConfiguration;

    @Override
    public 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 {
    @Autowired
    MyConfiguration myConfiguration;

    @Override
    public 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;

    @Autowired
    KafkaServiceImpl kafkaService;
    @Autowired
    MQServiceImpl mqService;

    public IBaseService get(){
        if (type.equals("kafka"))
            return kafkaService;
        else
            return mqService;
    }
}

5.方案一单元测试及测试结果

application.yaml

message:
  type: kafka

	@Autowired
	SendMessageUtil sendMessageUtil;
	@Test
	void contextLoadsTwo() {
		IBaseService tempBaseService = sendMessageUtil.get();
		tempBaseService.send();
	}

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 {
    @Override
    public 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 {

    @Override
    public 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
	@Autowired
	SendMessageUtil sendMessageUtil;
	@Test
	void contextLoadsTwo() {
		IBaseService tempBaseService = sendMessageUtil.get();
		tempBaseService.send();
	}

6.项目结构及源码

源码奉上，欢迎star！
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