SpringBoot2 高級(jí)應(yīng)用(14)： 整合 Drools規(guī)則引擎，實(shí)現(xiàn)高效的業(yè)務(wù)規(guī)則

本文源碼： GitHub·點(diǎn)這里 || GitEE·點(diǎn)這里

一、Drools引擎簡(jiǎn)介

1、基礎(chǔ)簡(jiǎn)介

Drools是一個(gè)基于java的規(guī)則引擎，開(kāi)源的，可以將復(fù)雜多變的規(guī)則從硬編碼中解放出來(lái)，以規(guī)則腳本的形式存放在文件中，使得規(guī)則的變更不需要修正代碼重啟機(jī)器就可以立即在線上環(huán)境生效。具有易于訪問(wèn)企業(yè)策略、易于調(diào)整以及易于管理的特點(diǎn)，作為開(kāi)源業(yè)務(wù)規(guī)則引擎，符合業(yè)內(nèi)標(biāo)準(zhǔn)，速度快、效率高。

2、規(guī)則語(yǔ)法

(1)、演示drl文件格式

package droolRule ;
import org.slf4j.Logger
import org.slf4j.LoggerFactory ;
dialect  "java"
rule "paramcheck1"
    when 
    then
        final Logger LOGGER = LoggerFactory.getLogger("param-check-one 規(guī)則引擎") ;
        LOGGER.info("參數(shù)");
end

(2)、語(yǔ)法說(shuō)明

· 文件格式
可以 .drl、xml文件，也可以Java代碼塊硬編碼;
· package
規(guī)則文件中，package是必須定義的，必須放在規(guī)則文件第一行;
· import
規(guī)則文件使用到的外部變量，可以是一個(gè)類，也可以是類中的可訪問(wèn)的靜態(tài)方法;
· rule
定義一個(gè)規(guī)則。paramcheck1規(guī)則名。規(guī)則通常包含三個(gè)部分：屬性、條件、結(jié)果;

二、整合SpringBoot框架

1、項(xiàng)目結(jié)構(gòu)

2、核心依賴

<!--drools規(guī)則引擎-->
<dependency>
    <groupId>org.drools</groupId>
    <artifactId>drools-core</artifactId>
    <version>7.6.0.Final</version>
</dependency>
<dependency>
    <groupId>org.drools</groupId>
    <artifactId>drools-compiler</artifactId>
    <version>7.6.0.Final</version>
</dependency>
<dependency>
    <groupId>org.drools</groupId>
    <artifactId>drools-templates</artifactId>
    <version>7.6.0.Final</version>
</dependency>
<dependency>
    <groupId>org.kie</groupId>
    <artifactId>kie-api</artifactId>
    <version>7.6.0.Final</version>
</dependency>
<dependency>
    <groupId>org.kie</groupId>
    <artifactId>kie-spring</artifactId>
    <version>7.6.0.Final</version>
</dependency>

3、配置文件

@Configuration
public class RuleEngineConfig {
    private static final Logger LOGGER = LoggerFactory.getLogger(RuleEngineConfig.class) ;
    private static final String RULES_PATH = "droolRule/";
    private final KieServices kieServices = KieServices.Factory.get();
    @Bean
    public KieFileSystem kieFileSystem() throws IOException {
        KieFileSystem kieFileSystem = kieServices.newKieFileSystem();
        ResourcePatternResolver resourcePatternResolver = new PathMatchingResourcePatternResolver();
        Resource[] files = resourcePatternResolver.getResources("classpath*:" + RULES_PATH + "*.*");
        String path = null;
        for (Resource file : files) {
            path = RULES_PATH + file.getFilename();
            LOGGER.info("path="+path);
            kieFileSystem.write(ResourceFactory.newClassPathResource(path, "UTF-8"));
        }
        return kieFileSystem;
    }
    @Bean
    public KieContainer kieContainer() throws IOException {
        KieRepository kieRepository = kieServices.getRepository();
        kieRepository.addKieModule(kieRepository::getDefaultReleaseId);
        KieBuilder kieBuilder = kieServices.newKieBuilder(kieFileSystem());
        kieBuilder.buildAll();
        return kieServices.newKieContainer(kieRepository.getDefaultReleaseId());
    }
    @Bean
    public KieBase kieBase() throws IOException {
        return kieContainer().getKieBase();
    }
    @Bean
    public KieSession kieSession() throws IOException {
        return kieContainer().newKieSession();
    }
    @Bean
    public KModuleBeanFactoryPostProcessor kiePostProcessor() {
        return new KModuleBeanFactoryPostProcessor();
    }
}

這樣環(huán)境整合就完成了。

三、演示案例

1、規(guī)則文件

• 規(guī)則一

  dialect  "java"
  rule "paramcheck1"
    salience 99
    when queryParam : QueryParam(paramId != null && paramSign.equals("+"))
        resultParam : RuleResult()
    then
        final Logger LOGGER = LoggerFactory.getLogger("param-check-one 規(guī)則引擎") ;
        LOGGER.info("參數(shù):getParamId="+queryParam.getParamId()+";getParamSign="+queryParam.getParamSign());
        RuleEngineServiceImpl ruleEngineService = new RuleEngineServiceImpl() ;
        ruleEngineService.executeAddRule(queryParam);
        resultParam.setPostCodeResult(true);
  end
  

• 規(guī)則二

  dialect  "java"
  rule "paramcheck2"
    salience 88
    when queryParam : QueryParam(paramId != null && paramSign.equals("-"))
        resultParam : RuleResult()
    then
        final Logger LOGGER = LoggerFactory.getLogger("param-check-two 規(guī)則引擎") ;
        LOGGER.info("參數(shù):getParamId="+queryParam.getParamId()+";getParamSign="+queryParam.getParamSign());
        RuleEngineServiceImpl ruleEngineService = new RuleEngineServiceImpl() ;
        ruleEngineService.executeRemoveRule(queryParam);
        resultParam.setPostCodeResult(true);
  end
  

規(guī)則說(shuō)明：

A、salience 的值越大，越優(yōu)先執(zhí)行；

B、規(guī)則流程：如果paramId不為null，參數(shù)標(biāo)識(shí)是+號(hào)，執(zhí)行添加規(guī)則，-號(hào)，執(zhí)行移除規(guī)則操作。

2、規(guī)則執(zhí)行代碼

@Service
public class RuleEngineServiceImpl implements RuleEngineService {
    private static final Logger LOGGER = LoggerFactory.getLogger(RuleEngineServiceImpl.class) ;
    @Override
    public void executeAddRule(QueryParam param) {
        LOGGER.info("參數(shù)數(shù)據(jù):"+param.getParamId()+";"+param.getParamSign());
        ParamInfo paramInfo = new ParamInfo() ;
        paramInfo.setId(param.getParamId());
        paramInfo.setParamSign(param.getParamSign());
        paramInfo.setCreateTime(new Date());
        paramInfo.setUpdateTime(new Date());
        ParamInfoService paramInfoService = (ParamInfoService)SpringContextUtil.getBean("paramInfoService") ;
        paramInfoService.insertParam(paramInfo);
    }
    @Override
    public void executeRemoveRule(QueryParam param) {
        LOGGER.info("參數(shù)數(shù)據(jù):"+param.getParamId()+";"+param.getParamSign());
        ParamInfoService paramInfoService = (ParamInfoService)SpringContextUtil.getBean("paramInfoService") ;
        ParamInfo paramInfo = paramInfoService.selectById(param.getParamId());
        if (paramInfo != null){
            paramInfoService.removeById(param.getParamId()) ;
        }
    }
}

3、規(guī)則調(diào)用接口

@RestController
@RequestMapping("/rule")
public class RuleController {
    @Resource
    private KieSession kieSession;
    @Resource
    private RuleEngineService ruleEngineService ;
    @RequestMapping("/param")
    public void param (){
        QueryParam queryParam1 = new QueryParam() ;
        queryParam1.setParamId("1");
        queryParam1.setParamSign("+");
        QueryParam queryParam2 = new QueryParam() ;
        queryParam2.setParamId("2");
        queryParam2.setParamSign("-");
        // 入?yún)?        kieSession.insert(queryParam1) ;
        kieSession.insert(queryParam2) ;
        kieSession.insert(this.ruleEngineService) ;
        // 返參
        RuleResult resultParam = new RuleResult() ;
        kieSession.insert(resultParam) ;
        kieSession.fireAllRules() ;
    }
}

這樣，完整的案例就結(jié)束了。

四、源代碼地址

GitHub·地址
https://github.com/cicadasmile/middle-ware-parent
GitEE·地址
https://gitee.com/cicadasmile/middle-ware-parent