spring cloud 规则引擎 demo

这里提供一个基于Spring Cloud和Drools规则引擎的简单demo，实现了根据用户输入的商品信息进行促销活动匹配的功能。

首先，需要在pom.xml文件中添加依赖：

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-stream-rabbit</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-stream-binder-rabbit</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-stream-schema</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-stream-schema-client</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-stream-schema-serde</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-stream-binder-kafka-streams</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-stream-binder-kafka-core</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-stream-binder-kafka</artifactId>
</dependency>
<dependency>
    <groupId>org.kie</groupId>
    <artifactId>kie-spring</artifactId>
    <version>7.62.0.Final</version>
</dependency>
<dependency>
    <groupId>org.drools</groupId>
    <artifactId>drools-core</artifactId>
    <version>7.62.0.Final</version>
</dependency>

接着，在application.yml文件中配置RabbitMQ的连接信息：

spring:
  rabbitmq:
    host: localhost
    port: 5672
    username: guest
    password: guest

然后，创建一个商品实体类Product：

public class Product {
    private String name;
    private int price;
    private String category;
    // getter和setter方法省略
}

接下来，创建一个规则引擎服务类RuleEngineService：

@Service
public class RuleEngineService {
    private final KieContainer kieContainer;

    public RuleEngineService(KieContainer kieContainer) {
        this.kieContainer = kieContainer;
    }

    public List<String> getProductPromotions(Product product) {
        List<String> promotions = new ArrayList<>();
        KieSession kieSession = kieContainer.newKieSession();
        kieSession.insert(product);
        kieSession.setGlobal("promotions", promotions);
        kieSession.fireAllRules();
        kieSession.dispose();
        return promotions;
    }
}

在这个服务类中，我们通过注入KieContainer来获取Drools规则引擎的实例，然后根据用户传入的商品信息，通过Drools规则引擎来匹配对应的促销活动，最终返回一个促销活动列表。

最后，创建一个消息消费者类MessageConsumer：

@EnableBinding(Sink.class)
public class MessageConsumer {
    private final RuleEngineService ruleEngineService;

    public MessageConsumer(RuleEngineService ruleEngineService) {
        this.ruleEngineService = ruleEngineService;
    }

    @StreamListener(target = Sink.INPUT)
    public void process(Product product) {
        List<String> promotions = ruleEngineService.getProductPromotions(product);
        System.out.println("商品名称：" + product.getName());
        System.out.println("促销活动列表：" + promotions);
    }
}

这个消费者类通过@EnableBinding注解来绑定消息通道，然后使用@StreamListener注解监听输入通道，获取用户传入的商品信息，并通过RuleEngineService来获取促销活动列表并输出。

这样，一个简单的Spring Cloud和Drools规则引擎的demo就完成了。