背景
最近,因工作需要做了规则引擎的调研,对比了多个规则引擎后,最终选择开源规则引擎Drools。
Drools的优点很多,而我决定使用Drools的原因主要是:
- 非常活跃的社区支持(JBoss支持);
- 快速的执行速度;
- 完善的功能;
- 国外金融领域使用比较多;
当然,Drools也有很多缺点:
- 复杂(功能越多也意味着越复杂);
- 文档欠缺(官方文档混乱、缺少中文文档);
- 学习成本高;
为了能完全掌控Drools,最近一直在学习,使用各种方法学习Drools,通过在线文章、官方文档、官方API、视频教程等学习,并且有潜伏进一个Drools学习交流群,发现群里同学问的最多的一个问题就是:怎么样通过数据库动态加载规则?正好,我们也打算采用从数据库动态加载规则,并且我正好解决了这个问题,现在写篇文章分享出来给大家,希望能帮助到大家。
事例
事例说明
首先,通过代码生成规则模拟从数据库查询规则,每条规则记录包含:id(规则id,全局唯一)、sceneId(场景id,一个场景对应多个规则)、content(规则内容,既drl文件内容)。
然后,按场景动态加载规则,每个场景对应一个实际的业务场景,通过场景隔离不同的业务。
最后,执行应用指定场景规则,模拟不同业务场景下的规则应用。
事例实现
1. 创建Maven项目,引入依赖
<properties>
<drools.version>7.20.0.Final</drools.version>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.kie</groupId>
<artifactId>kie-api</artifactId>
<version>${drools.version}</version>
</dependency>
<dependency>
<groupId>org.drools</groupId>
<artifactId>drools-core</artifactId>
<version>${drools.version}</version>
</dependency>
<dependency>
<groupId>org.drools</groupId>
<artifactId>drools-compiler</artifactId>
<version>${drools.version}</version>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
2. 创建规则记录结构
package com.loujinhe.droolsdynamicloading.model;
import lombok.Data;
import lombok.ToString;
/**
* 规则信息
*
* @author loujinhe
* @date 2019/4/14 00:13
*/
@Data
@ToString
public class RuleInfo {
/**
* 规则id,全局唯一
*/
private Long id;
/**
* 场景id,一个场景对应多个规则,一个场景对应一个业务场景,一个场景对应一个kmodule
*/
private Long sceneId;
/**
* 规则内容,既drl文件内容
*/
private String content;
}
3. 创建规则查询接口
这里通过代码生成规则记录模拟从数据库查询规则记录。
package com.loujinhe.droolsdynamicloading.service;
import com.loujinhe.droolsdynamicloading.model.RuleInfo;
import org.springframework.stereotype.Service;
import java.text.MessageFormat;
import java.text.SimpleDateFormat;
import java.util.*;
/**
* 规则信息业务
*
* @author loujinhe
* @date 2019/4/14 00:20
*/
@Service
public class RuleInfoService {
/**
* 获取给定场景下的规则信息列表
*
* @param sceneId 场景ID
* @return 规则列表
*/
public List<RuleInfo> getRuleInfoListBySceneId(Long sceneId) {
Map<Long, List<RuleInfo>> sceneId2RuleInfoListMap = getRuleInfoListMap();
return sceneId2RuleInfoListMap.get(sceneId);
}
/**
* 获取场景与规则信息列表的Map
*
* @return 场景规则信息列表Map,Map(sceneId : List < RuleInfo >)
*/
public Map<Long, List<RuleInfo>> getRuleInfoListMap() {
Map<Long, List<RuleInfo>> sceneId2RuleInfoListMap = new HashMap<>();
List<RuleInfo> allRuleInfos = generateRuleInfoList();
for (RuleInfo ruleInfo : allRuleInfos) {
List<RuleInfo> ruleInfos = sceneId2RuleInfoListMap.computeIfAbsent(ruleInfo.getSceneId(), k -> new ArrayList<>());
ruleInfos.add(ruleInfo);
}
return sceneId2RuleInfoListMap;
}
/**
* 生成规则信息列表,注意场景id和规则id的对应关系
*
* @return 规则信息列表
*/
private List<RuleInfo> generateRuleInfoList() {
int sceneNum = 5;
int ruleNumPerScene = 3;
int sceneFactor = 10000;
List<RuleInfo> ruleInfos = new ArrayList<>(sceneNum * ruleNumPerScene);
for (int i = 0; i < sceneNum; i++) {
long sceneId = sceneFactor * (i + 1);
for (int j = 0; j < ruleNumPerScene; j++) {
long id = sceneId + (j + 1);
ruleInfos.add(generateRuleInfo(sceneId, id));
}
}
return ruleInfos;
}
/**
* 生成规则信息
*
* @param sceneId 场景ID
* @param id 规则ID
* @return 规则信息
*/
private RuleInfo generateRuleInfo(long sceneId, long id) {
RuleInfo ruleInfo = new RuleInfo();
ruleInfo.setId(id);
ruleInfo.setSceneId(sceneId);
ruleInfo.setContent(generateRuleContent(sceneId, id));
return ruleInfo;
}
/**
* 生成规则内容,每个场景id对应一个package,每个规则对应一个唯一的规则名
*
* 每次生成规则时记录时间戳,用来验证动态加载效果
*
* @param sceneId 场景ID
* @param id 规则ID
* @return 规则内容
*/
private String generateRuleContent(long sceneId, long id) {
String sceneIdStr = String.valueOf(sceneId);
String idStr = String.valueOf(id);
String nowStr = new SimpleDateFormat("yyyyMMddHHmmss").format(new Date());
String content = "package rules.scene_{0};\n" +
"\n" +
"rule \"rule_{1}\"\n" +
" when\n" +
" eval(true);\n" +
" then\n" +
" System.out.println(\"{2} [{3}, {4}]\");\n" +
"end\n";
return MessageFormat.format(content, sceneIdStr, idStr, nowStr, sceneIdStr, idStr);
}
}
4. 创建规则加载器
可以加载全部场景下的规则,也可以加载指定场景下的规则。
package com.loujinhe.droolsdynamicloading.drools;
import com.loujinhe.droolsdynamicloading.model.RuleInfo;
import com.loujinhe.droolsdynamicloading.service.RuleInfoService;
import org.kie.api.KieServices;
import org.kie.api.builder.KieBuilder;
import org.kie.api.builder.KieFileSystem;
import org.kie.api.builder.Message;
import org.kie.api.builder.Results;
import org.kie.api.builder.model.KieBaseModel;
import org.kie.api.builder.model.KieModuleModel;
import org.kie.api.runtime.KieContainer;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.ApplicationArguments;
import org.springframework.boot.ApplicationRunner;
import org.springframework.stereotype.Component;
import java.text.MessageFormat;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
/**
* 规则加载器
*
* @author loujinhe
* @date 2019/4/14 00:06
*/
@Component
public class RuleLoader implements ApplicationRunner {
/**
* key:kcontainerName,value:KieContainer,每个场景对应一个KieContainer
*/
private final ConcurrentMap<String, KieContainer> kieContainerMap = new ConcurrentHashMap<>();
@Autowired
private RuleInfoService ruleInfoService;
@Override
public void run(ApplicationArguments args) throws Exception {
reloadAll();
}
/**
* 构造kcontainerName
*
* @param sceneId 场景ID
* @return kcontainerName
*/
private String buildKcontainerName(long sceneId) {
return "kcontainer_" + sceneId;
}
/**
* 构造kbaseName
*
* @param sceneId 场景ID
* @return kbaseName
*/
private String buildKbaseName(long sceneId) {
return "kbase_" + sceneId;
}
/**
* 构造ksessionName
*
* @param sceneId 场景ID
* @return ksessionName
*/
private String buildKsessionName(long sceneId) {
return "ksession_" + sceneId;
}
KieContainer getKieContainerBySceneId(long sceneId) {
return kieContainerMap.get(buildKcontainerName(sceneId));
}
/**
* 重新加载所有规则
*/
public void reloadAll() {
Map<Long, List<RuleInfo>> sceneId2RuleInfoListMap = ruleInfoService.getRuleInfoListMap();
for (Map.Entry<Long, List<RuleInfo>> entry : sceneId2RuleInfoListMap.entrySet()) {
long sceneId = entry.getKey();
reload(sceneId, entry.getValue());
}
System.out.println("reload all success");
}
/**
* 重新加载给定场景下的规则
*
* @param sceneId 场景ID
*/
public void reload(Long sceneId) {
List<RuleInfo> ruleInfos = ruleInfoService.getRuleInfoListBySceneId(sceneId);
reload(sceneId, ruleInfos);
System.out.println("reload success");
}
/**
* 重新加载给定场景给定规则列表,对应一个kmodule
*
* @param sceneId 场景ID
* @param ruleInfos 规则列表
*/
private void reload(long sceneId, List<RuleInfo> ruleInfos) {
KieServices kieServices = KieServices.get();
KieModuleModel kieModuleModel = kieServices.newKieModuleModel();
KieBaseModel kieBaseModel = kieModuleModel.newKieBaseModel(buildKbaseName(sceneId));
kieBaseModel.setDefault(true);
kieBaseModel.addPackage(MessageFormat.format("rules.scene_{0}", String.valueOf(sceneId)));
kieBaseModel.newKieSessionModel(buildKsessionName(sceneId));
KieFileSystem kieFileSystem = kieServices.newKieFileSystem();
for (RuleInfo ruleInfo : ruleInfos) {
String fullPath = MessageFormat.format("src/main/resources/rules/scene_{0}/rule_{1}.drl", String.valueOf(sceneId), String.valueOf(ruleInfo.getId()));
kieFileSystem.write(fullPath, ruleInfo.getContent());
}
kieFileSystem.writeKModuleXML(kieModuleModel.toXML());
KieBuilder kieBuilder = kieServices.newKieBuilder(kieFileSystem).buildAll();
Results results = kieBuilder.getResults();
if (results.hasMessages(Message.Level.ERROR)) {
System.out.println(results.getMessages());
throw new IllegalStateException("rule error");
}
KieContainer kieContainer = kieServices.newKieContainer(kieServices.getRepository().getDefaultReleaseId());
kieContainerMap.put(buildKcontainerName(sceneId), kieContainer);
}
}
5. 创建KieSession辅助类
通过该辅助类可以获取指定场景下的KieSession,通过该KieSession可以与指定场景规则交互。
package com.loujinhe.droolsdynamicloading.drools;
import org.kie.api.runtime.KieSession;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
/**
* KieSession助手类
*
* @author loujinhe
* @date 2019/4/15 22:29
*/
@Component
public class KieSessionHelper {
@Autowired
private RuleLoader ruleLoader;
/**
* 获取KieSession
*
* @param sceneId 场景ID
* @return KieSession
*/
public KieSession getKieSessionBySceneId(long sceneId) {
return ruleLoader.getKieContainerBySceneId(sceneId).getKieBase().newKieSession();
}
}
6. 创建业务入口
包含动态加载指定场景规则功能,以及触发指定场景下的规则功能。
package com.loujinhe.droolsdynamicloading.controller;
import com.loujinhe.droolsdynamicloading.drools.KieSessionHelper;
import com.loujinhe.droolsdynamicloading.drools.RuleLoader;
import org.kie.api.runtime.KieSession;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
/**
* 规则测试
*
* @author loujinhe
* @date 2019/4/14 01:35
*/
@RequestMapping("rule")
@RestController
public class RuleController {
@Autowired
private RuleLoader ruleLoader;
@Autowired
private KieSessionHelper kieSessionHelper;
@GetMapping("/")
public String index() {
System.out.println("index");
return "success";
}
/**
* 重新加载所有规则
*/
@GetMapping("reload")
public String reload() {
System.out.println("reload all");
ruleLoader.reloadAll();
return "success";
}
/**
* 重新加载给定场景下的规则
*
* @param sceneId 场景ID
*/
@GetMapping("reload/{sceneId}")
public String reload(@PathVariable("sceneId") Long sceneId) {
System.out.println("reload scene:" + sceneId);
ruleLoader.reload(sceneId);
return "success";
}
/**
* 触发给定场景规则
*
* @param sceneId 场景ID
*/
@GetMapping("fire/{sceneId}")
public String fire(@PathVariable("sceneId") Long sceneId) {
System.out.println("fire scene:" + sceneId);
KieSession kieSession = kieSessionHelper.getKieSessionBySceneId(sceneId);
kieSession.fireAllRules();
kieSession.dispose();
return "success";
}
}
7. 启动服务
默认加载所有场景下的规则,启动时日志如下:
/Library/Java/JavaVirtualMachines/jdk1.8.0_181.jdk/Contents/Home/bin/java -XX:TieredStopAtLevel=1 -noverify -Dspring.output.ansi.enabled=always -Dcom.sun.management.jmxremote -Dcom.sun.management.jmxremote.port=54524 -Dcom.sun.management.jmxremote.authenticate=false -Dcom.sun.management.jmxremote.ssl=false -Djava.rmi.server.hostname=127.0.0.1 -Dspring.liveBeansView.mbeanDomain -Dspring.application.admin.enabled=true "-javaagent:/Applications/IntelliJ IDEA.app/Contents/lib/idea_rt.jar=54525:/Applications/IntelliJ IDEA.app/Contents/bin" -Dfile.encoding=UTF-8 -classpath /Library/Java/JavaVirtualMachines/jdk1.8.0_181.jdk/Contents/Home/jre/lib/charsets.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_181.jdk/Contents/Home/jre/lib/deploy.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_181.jdk/Contents/Home/jre/lib/ext/cldrdata.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_181.jdk/Contents/Home/jre/lib/ext/dnsns.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_181.jdk/Contents/Home/jre/lib/ext/jaccess.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_181.jdk/Contents/Home/jre/lib/ext/jfxrt.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_181.jdk/Contents/Home/jre/lib/ext/localedata.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_181.jdk/Contents/Home/jre/lib/ext/nashorn.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_181.jdk/Contents/Home/jre/lib/ext/sunec.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_181.jdk/Contents/Home/jre/lib/ext/sunjce_provider.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_181.jdk/Contents/Home/jre/lib/ext/sunpkcs11.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_181.jdk/Contents/Home/jre/lib/ext/zipfs.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_181.jdk/Contents/Home/jre/lib/javaws.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_181.jdk/Contents/Home/jre/lib/jce.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_181.jdk/Contents/Home/jre/lib/jfr.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_181.jdk/Contents/Home/jre/lib/jfxswt.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_181.jdk/Contents/Home/jre/lib/jsse.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_181.jdk/Contents/Home/jre/lib/management-agent.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_181.jdk/Contents/Home/jre/lib/plugin.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_181.jdk/Contents/Home/jre/lib/resources.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_181.jdk/Contents/Home/jre/lib/rt.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_181.jdk/Contents/Home/lib/ant-javafx.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_181.jdk/Contents/Home/lib/dt.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_181.jdk/Contents/Home/lib/javafx-mx.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_181.jdk/Contents/Home/lib/jconsole.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_181.jdk/Contents/Home/lib/packager.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_181.jdk/Contents/Home/lib/sa-jdi.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_181.jdk/Contents/Home/lib/tools.jar:/Users/loujinhe/project/IdeaProjects/drools-dynamic-loading/target/classes:/Users/loujinhe/.m2/repository/org/kie/kie-api/7.20.0.Final/kie-api-7.20.0.Final.jar:/Users/loujinhe/.m2/repository/org/kie/soup/kie-soup-maven-support/7.20.0.Final/kie-soup-maven-support-7.20.0.Final.jar:/Users/loujinhe/.m2/repository/org/slf4j/slf4j-api/1.7.26/slf4j-api-1.7.26.jar:/Users/loujinhe/.m2/repository/org/drools/drools-core/7.20.0.Final/drools-core-7.20.0.Final.jar:/Users/loujinhe/.m2/repository/org/mvel/mvel2/2.4.4.Final/mvel2-2.4.4.Final.jar:/Users/loujinhe/.m2/repository/org/kie/kie-internal/7.20.0.Final/kie-internal-7.20.0.Final.jar:/Users/loujinhe/.m2/repository/org/kie/soup/kie-soup-commons/7.20.0.Final/kie-soup-commons-7.20.0.Final.jar:/Users/loujinhe/.m2/repository/org/kie/soup/kie-soup-project-datamodel-commons/7.20.0.Final/kie-soup-project-datamodel-commons-7.20.0.Final.jar:/Users/loujinhe/.m2/repository/org/kie/soup/kie-soup-project-datamodel-api/7.20.0.Final/kie-soup-project-datamodel-api-7.20.0.Final.jar:/Users/loujinhe/.m2/repository/commons-codec/commons-codec/1.11/commons-codec-1.11.jar:/Users/loujinhe/.m2/repository/org/drools/drools-compiler/7.20.0.Final/drools-compiler-7.20.0.Final.jar:/Users/loujinhe/.m2/repository/org/antlr/antlr-runtime/3.5.2/antlr-runtime-3.5.2.jar:/Users/loujinhe/.m2/repository/org/eclipse/jdt/core/compiler/ecj/4.6.1/ecj-4.6.1.jar:/Users/loujinhe/.m2/repository/com/thoughtworks/xstream/xstream/1.4.10/xstream-1.4.10.jar:/Users/loujinhe/.m2/repository/xmlpull/xmlpull/1.1.3.1/xmlpull-1.1.3.1.jar:/Users/loujinhe/.m2/repository/xpp3/xpp3_min/1.1.4c/xpp3_min-1.1.4c.jar:/Users/loujinhe/.m2/repository/com/google/protobuf/protobuf-java/3.6.1/protobuf-java-3.6.1.jar:/Users/loujinhe/.m2/repository/org/projectlombok/lombok/1.18.6/lombok-1.18.6.jar:/Users/loujinhe/.m2/repository/org/springframework/boot/spring-boot-starter-web/2.1.4.RELEASE/spring-boot-starter-web-2.1.4.RELEASE.jar:/Users/loujinhe/.m2/repository/org/springframework/boot/spring-boot-starter/2.1.4.RELEASE/spring-boot-starter-2.1.4.RELEASE.jar:/Users/loujinhe/.m2/repository/org/springframework/boot/spring-boot/2.1.4.RELEASE/spring-boot-2.1.4.RELEASE.jar:/Users/loujinhe/.m2/repository/org/springframework/boot/spring-boot-autoconfigure/2.1.4.RELEASE/spring-boot-autoconfigure-2.1.4.RELEASE.jar:/Users/loujinhe/.m2/repository/org/springframework/boot/spring-boot-starter-logging/2.1.4.RELEASE/spring-boot-starter-logging-2.1.4.RELEASE.jar:/Users/loujinhe/.m2/repository/ch/qos/logback/logback-classic/1.2.3/logback-classic-1.2.3.jar:/Users/loujinhe/.m2/repository/ch/qos/logback/logback-core/1.2.3/logback-core-1.2.3.jar:/Users/loujinhe/.m2/repository/org/apache/logging/log4j/log4j-to-slf4j/2.11.2/log4j-to-slf4j-2.11.2.jar:/Users/loujinhe/.m2/repository/org/apache/logging/log4j/log4j-api/2.11.2/log4j-api-2.11.2.jar:/Users/loujinhe/.m2/repository/org/slf4j/jul-to-slf4j/1.7.26/jul-to-slf4j-1.7.26.jar:/Users/loujinhe/.m2/repository/javax/annotation/javax.annotation-api/1.3.2/javax.annotation-api-1.3.2.jar:/Users/loujinhe/.m2/repository/org/yaml/snakeyaml/1.23/snakeyaml-1.23.jar:/Users/loujinhe/.m2/repository/org/springframework/boot/spring-boot-starter-json/2.1.4.RELEASE/spring-boot-starter-json-2.1.4.RELEASE.jar:/Users/loujinhe/.m2/repository/com/fasterxml/jackson/core/jackson-databind/2.9.8/jackson-databind-2.9.8.jar:/Users/loujinhe/.m2/repository/com/fasterxml/jackson/core/jackson-annotations/2.9.0/jackson-annotations-2.9.0.jar:/Users/loujinhe/.m2/repository/com/fasterxml/jackson/core/jackson-core/2.9.8/jackson-core-2.9.8.jar:/Users/loujinhe/.m2/repository/com/fasterxml/jackson/datatype/jackson-datatype-jdk8/2.9.8/jackson-datatype-jdk8-2.9.8.jar:/Users/loujinhe/.m2/repository/com/fasterxml/jackson/datatype/jackson-datatype-jsr310/2.9.8/jackson-datatype-jsr310-2.9.8.jar:/Users/loujinhe/.m2/repository/com/fasterxml/jackson/module/jackson-module-parameter-names/2.9.8/jackson-module-parameter-names-2.9.8.jar:/Users/loujinhe/.m2/repository/org/springframework/boot/spring-boot-starter-tomcat/2.1.4.RELEASE/spring-boot-starter-tomcat-2.1.4.RELEASE.jar:/Users/loujinhe/.m2/repository/org/apache/tomcat/embed/tomcat-embed-core/9.0.17/tomcat-embed-core-9.0.17.jar:/Users/loujinhe/.m2/repository/org/apache/tomcat/embed/tomcat-embed-el/9.0.17/tomcat-embed-el-9.0.17.jar:/Users/loujinhe/.m2/repository/org/apache/tomcat/embed/tomcat-embed-websocket/9.0.17/tomcat-embed-websocket-9.0.17.jar:/Users/loujinhe/.m2/repository/org/hibernate/validator/hibernate-validator/6.0.16.Final/hibernate-validator-6.0.16.Final.jar:/Users/loujinhe/.m2/repository/javax/validation/validation-api/2.0.1.Final/validation-api-2.0.1.Final.jar:/Users/loujinhe/.m2/repository/org/jboss/logging/jboss-logging/3.3.2.Final/jboss-logging-3.3.2.Final.jar:/Users/loujinhe/.m2/repository/com/fasterxml/classmate/1.4.0/classmate-1.4.0.jar:/Users/loujinhe/.m2/repository/org/springframework/spring-web/5.1.6.RELEASE/spring-web-5.1.6.RELEASE.jar:/Users/loujinhe/.m2/repository/org/springframework/spring-beans/5.1.6.RELEASE/spring-beans-5.1.6.RELEASE.jar:/Users/loujinhe/.m2/repository/org/springframework/spring-webmvc/5.1.6.RELEASE/spring-webmvc-5.1.6.RELEASE.jar:/Users/loujinhe/.m2/repository/org/springframework/spring-aop/5.1.6.RELEASE/spring-aop-5.1.6.RELEASE.jar:/Users/loujinhe/.m2/repository/org/springframework/spring-context/5.1.6.RELEASE/spring-context-5.1.6.RELEASE.jar:/Users/loujinhe/.m2/repository/org/springframework/spring-expression/5.1.6.RELEASE/spring-expression-5.1.6.RELEASE.jar:/Users/loujinhe/.m2/repository/org/springframework/spring-core/5.1.6.RELEASE/spring-core-5.1.6.RELEASE.jar:/Users/loujinhe/.m2/repository/org/springframework/spring-jcl/5.1.6.RELEASE/spring-jcl-5.1.6.RELEASE.jar com.loujinhe.droolsdynamicloading.DroolsDynamicLoadingApplication
. ____ _ __ _ _
/\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
\\/ ___)| |_)| | | | | || (_| | ) ) ) )
' |____| .__|_| |_|_| |_\__, | / / / /
=========|_|==============|___/=/_/_/_/
:: Spring Boot :: (v2.1.4.RELEASE)
2019-05-11 01:26:16.189 INFO 5866 --- [ main] c.l.d.DroolsDynamicLoadingApplication : Starting DroolsDynamicLoadingApplication on loujinhedeMacBook-Pro.local with PID 5866 (/Users/loujinhe/project/IdeaProjects/drools-dynamic-loading/target/classes started by loujinhe in /Users/loujinhe/project/IdeaProjects/drools-dynamic-loading)
2019-05-11 01:26:16.191 INFO 5866 --- [ main] c.l.d.DroolsDynamicLoadingApplication : No active profile set, falling back to default profiles: default
2019-05-11 01:26:16.836 INFO 5866 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat initialized with port(s): 8080 (http)
2019-05-11 01:26:16.851 INFO 5866 --- [ main] o.apache.catalina.core.StandardService : Starting service [Tomcat]
2019-05-11 01:26:16.851 INFO 5866 --- [ main] org.apache.catalina.core.StandardEngine : Starting Servlet engine: [Apache Tomcat/9.0.17]
2019-05-11 01:26:16.910 INFO 5866 --- [ main] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring embedded WebApplicationContext
2019-05-11 01:26:16.910 INFO 5866 --- [ main] o.s.web.context.ContextLoader : Root WebApplicationContext: initialization completed in 696 ms
2019-05-11 01:26:17.052 INFO 5866 --- [ main] o.s.s.concurrent.ThreadPoolTaskExecutor : Initializing ExecutorService 'applicationTaskExecutor'
2019-05-11 01:26:17.203 INFO 5866 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat started on port(s): 8080 (http) with context path ''
2019-05-11 01:26:17.206 INFO 5866 --- [ main] c.l.d.DroolsDynamicLoadingApplication : Started DroolsDynamicLoadingApplication in 1.224 seconds (JVM running for 1.626)
2019-05-11 01:26:17.220 INFO 5866 --- [ main] o.k.a.i.utils.ServiceDiscoveryImpl : Loading kie.conf from jar:file:/Users/loujinhe/.m2/repository/org/drools/drools-core/7.20.0.Final/drools-core-7.20.0.Final.jar!/META-INF/kie.conf in classloader sun.misc.Launcher$AppClassLoader@18b4aac2
2019-05-11 01:26:17.221 INFO 5866 --- [ main] o.k.a.i.utils.ServiceDiscoveryImpl : Adding Service org.drools.core.io.impl.ResourceFactoryServiceImpl
2019-05-11 01:26:17.222 INFO 5866 --- [ main] o.k.a.i.utils.ServiceDiscoveryImpl : Adding Service org.drools.core.marshalling.impl.MarshallerProviderImpl
2019-05-11 01:26:17.222 INFO 5866 --- [ main] o.k.a.i.utils.ServiceDiscoveryImpl : Adding Service org.drools.core.concurrent.ExecutorProviderImpl
2019-05-11 01:26:17.222 INFO 5866 --- [ main] o.k.a.i.utils.ServiceDiscoveryImpl : Loading kie.conf from jar:file:/Users/loujinhe/.m2/repository/org/kie/kie-internal/7.20.0.Final/kie-internal-7.20.0.Final.jar!/META-INF/kie.conf in classloader sun.misc.Launcher$AppClassLoader@18b4aac2
2019-05-11 01:26:17.223 INFO 5866 --- [ main] o.k.a.i.utils.ServiceDiscoveryImpl : Adding Service org.kie.internal.services.KieAssemblersImpl
2019-05-11 01:26:17.223 INFO 5866 --- [ main] o.k.a.i.utils.ServiceDiscoveryImpl : Adding Service org.kie.internal.services.KieRuntimesImpl
2019-05-11 01:26:17.224 INFO 5866 --- [ main] o.k.a.i.utils.ServiceDiscoveryImpl : Adding Service org.kie.internal.services.KieWeaversImpl
2019-05-11 01:26:17.224 INFO 5866 --- [ main] o.k.a.i.utils.ServiceDiscoveryImpl : Adding Service org.kie.internal.services.KieBeliefsImpl
2019-05-11 01:26:17.224 INFO 5866 --- [ main] o.k.a.i.utils.ServiceDiscoveryImpl : Loading kie.conf from jar:file:/Users/loujinhe/.m2/repository/org/drools/drools-compiler/7.20.0.Final/drools-compiler-7.20.0.Final.jar!/META-INF/kie.conf in classloader sun.misc.Launcher$AppClassLoader@18b4aac2
2019-05-11 01:26:17.225 INFO 5866 --- [ main] o.k.a.i.utils.ServiceDiscoveryImpl : Adding Service org.drools.compiler.kie.builder.impl.KieServicesImpl
2019-05-11 01:26:17.226 INFO 5866 --- [ main] o.k.a.i.utils.ServiceDiscoveryImpl : Adding Service org.drools.compiler.builder.impl.KnowledgeBuilderFactoryServiceImpl
2019-05-11 01:26:17.778 INFO 5866 --- [ main] o.d.c.k.builder.impl.KieRepositoryImpl : KieModule was added: MemoryKieModule[releaseId=org.default:artifact:1.0.0]
2019-05-11 01:26:17.800 INFO 5866 --- [ main] o.d.c.k.builder.impl.KieRepositoryImpl : KieModule was added: MemoryKieModule[releaseId=org.default:artifact:1.0.0]
2019-05-11 01:26:17.816 INFO 5866 --- [ main] o.d.c.k.builder.impl.KieRepositoryImpl : KieModule was added: MemoryKieModule[releaseId=org.default:artifact:1.0.0]
2019-05-11 01:26:17.831 INFO 5866 --- [ main] o.d.c.k.builder.impl.KieRepositoryImpl : KieModule was added: MemoryKieModule[releaseId=org.default:artifact:1.0.0]
2019-05-11 01:26:17.846 INFO 5866 --- [ main] o.d.c.k.builder.impl.KieRepositoryImpl : KieModule was added: MemoryKieModule[releaseId=org.default:artifact:1.0.0]
reload all success
8. 验证
8.1 首先,分别触发场景10000、20000、30000下的规则,访问url及日志如下:
http://localhost:8080/rule/fire/10000
http://localhost:8080/rule/fire/20000
http://localhost:8080/rule/fire/30000
2019-05-11 01:32:01.844 INFO 5866 --- [nio-8080-exec-1] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring DispatcherServlet 'dispatcherServlet'
2019-05-11 01:32:01.844 INFO 5866 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet : Initializing Servlet 'dispatcherServlet'
2019-05-11 01:32:01.851 INFO 5866 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet : Completed initialization in 7 ms
fire scene:10000
20190511012617 [10000, 10002]
20190511012617 [10000, 10003]
20190511012617 [10000, 10001]
fire scene:20000
20190511012617 [20000, 20001]
20190511012617 [20000, 20003]
20190511012617 [20000, 20002]
fire scene:30000
20190511012617 [30000, 30001]
20190511012617 [30000, 30002]
20190511012617 [30000, 30003]
通过分析日志发现,规则是按场景隔离的,并且规则的生成时间戳都是:20190511012617。
8.2 然后,加载场景20000下的规则,访问url及日志如下:
http://localhost:8080/rule/reload/20000
reload scene:20000
2019-05-11 01:34:45.988 INFO 5866 --- [nio-8080-exec-9] o.d.c.k.builder.impl.KieRepositoryImpl : KieModule was added: MemoryKieModule[releaseId=org.default:artifact:1.0.0]
reload success
通过分析日志发现,规则加载成功(应该)。
8.3 最后,分别触发场景10000、20000、30000下的规则,访问url及日志如下:
http://localhost:8080/rule/fire/10000
http://localhost:8080/rule/fire/20000
http://localhost:8080/rule/fire/30000
fire scene:10000
20190511012617 [10000, 10002]
20190511012617 [10000, 10003]
20190511012617 [10000, 10001]
fire scene:20000
20190511013445 [20000, 20001]
20190511013445 [20000, 20002]
20190511013445 [20000, 20003]
fire scene:30000
20190511012617 [30000, 30001]
20190511012617 [30000, 30002]
20190511012617 [30000, 30003]
通过分析日志发现,场景10000、30000的时间戳是一样的,跟第一次加载时的时间戳是一样的,而场景20000的时间戳不一样,为20190511013445正好是我们刚才手动动态加载时的时间戳,说明动态加载指定场景规则成功。
事例总结
整个动态加载规则的核心代码就几行,核心代码如下:
/**
* 重新加载给定场景给定规则列表,对应一个kmodule
*
* @param sceneId 场景ID
* @param ruleInfos 规则列表
*/
private void reload(long sceneId, List<RuleInfo> ruleInfos) {
KieServices kieServices = KieServices.get();
KieModuleModel kieModuleModel = kieServices.newKieModuleModel();
KieBaseModel kieBaseModel = kieModuleModel.newKieBaseModel(buildKbaseName(sceneId));
kieBaseModel.setDefault(true);
kieBaseModel.addPackage(MessageFormat.format("rules.scene_{0}", String.valueOf(sceneId)));
kieBaseModel.newKieSessionModel(buildKsessionName(sceneId));
KieFileSystem kieFileSystem = kieServices.newKieFileSystem();
for (RuleInfo ruleInfo : ruleInfos) {
String fullPath = MessageFormat.format("src/main/resources/rules/scene_{0}/rule_{1}.drl", String.valueOf(sceneId), String.valueOf(ruleInfo.getId()));
kieFileSystem.write(fullPath, ruleInfo.getContent());
}
kieFileSystem.writeKModuleXML(kieModuleModel.toXML());
KieBuilder kieBuilder = kieServices.newKieBuilder(kieFileSystem).buildAll();
Results results = kieBuilder.getResults();
if (results.hasMessages(Message.Level.ERROR)) {
System.out.println(results.getMessages());
throw new IllegalStateException("rule error");
}
KieContainer kieContainer = kieServices.newKieContainer(kieServices.getRepository().getDefaultReleaseId());
kieContainerMap.put(buildKcontainerName(sceneId), kieContainer);
}
通过分析代码发现,动态加载规则的方式跟通过kmodule.xml配置文件加载规则的方式是对应的,如:KieModuleModel 对应kmodule节点,KieBaseModel对应kbase节点,并且最终也是通过转换成kmodule.xml配置文件的方式加载规则的,如:kieFileSystem.writeKModuleXML(kieModuleModel.toXML())。
总结
Drools很好很强大,文档很烂很差劲,希望我的绵薄之力可以节省大家的宝贵时间。