org.jeasy:easy-rules-core:4.1.0
org.jeasy:easy-rules-support:4.1.0
org.jeasy:easy-rules-mvel:4.1.0
com.alibaba.nacos:nacos-client:2.2.0



test_rule_001
yaml 规则 

name: "alcohol rule"
description: "children are not allowed to buy alcohol"
priority: 1
condition: "person.age < 18"
actions:
  - "System.out.println(\"Shop: Sorry, you are not allowed to buy alcohol\");"



public class Person {
    private String name;
    private int age;



import com.alibaba.nacos.api.NacosFactory;
import com.alibaba.nacos.api.config.ConfigService;
import org.jeasy.rules.api.Facts;
import org.jeasy.rules.api.Rule;
import org.jeasy.rules.api.Rules;
import org.jeasy.rules.api.RulesEngine;
import org.jeasy.rules.core.DefaultRulesEngine;
import org.jeasy.rules.mvel.MVELRuleFactory;
import org.jeasy.rules.support.reader.YamlRuleDefinitionReader;

import java.io.StringReader;
import java.util.Properties;

public class RuleDemo {

    public static void main(String[] args) throws Exception {

        // 从 nacos 读取规则
        Properties properties = new Properties();
        properties.setProperty("serverAddr", "127.0.0.1:8848");
        ConfigService configService = NacosFactory.createConfigService(properties);
        String dataId = "test_rule_001";
        String group = "DEFAULT_GROUP";
        long timeoutMs = 3000;
        String rule = configService.getConfig(dataId,group,timeoutMs);
        System.out.println(rule);
        System.out.println("---------------");


        // 创建规则  mvel 脚本
        MVELRuleFactory ruleFactory = new MVELRuleFactory(new YamlRuleDefinitionReader());
        Rule alcoholRule = ruleFactory.createRule(new StringReader(rule));

        // create a rule set
        Rules rules = new Rules();
        rules.register(alcoholRule);

        //create a default rules engine and fire rules on known facts
        RulesEngine rulesEngine = new DefaultRulesEngine();

        //create a person instance (fact)
        Person tom = new Person("Tom", 15);
        Facts facts = new Facts();
        facts.put("person", tom);


        System.out.println("Tom: Hi! can I have some Vodka please?");
        // 运行规则引擎
        rulesEngine.fire(rules, facts);
    }

}




 nacos 配置安装 

 nacos Java客户端使用 


https://gitee.com/dyyx/work2024/tree/master/demo/easyrules-nacos-demo