规则引擎drools封装

一.前言

    网上规则引擎drools介绍很多,并且有很多细致的说明,作者也不敢托大说自己的好用,但作者经过2个项目使用过规则引擎后,自己对规则引擎的理解并进行封装,对规则内容及如何使用,有自己的一番实践,并提供源代码,供大家参考


二.设计思路及具体代码

    首先我希望是轻量级的使用drools,不希望使用太过复杂的架构,以这种思路入手,就可以与任何项目轻易融入,这样就需要能够将drools规则的来源,从规则文件(drl)中可以从maven和自己的数据库中获取,脚本是动态的,配合drools6.5支持通过maven接入的规则的API,就可以做到从任何处获取规则内容

一个工具类DroolsUtils

  1. package com.vip.jie.rule.util;
  2.  
  3. import org.drools.compiler.kie.builder.impl.InternalKieModule;
  4. import org.kie.api.KieServices;
  5. import org.kie.api.builder.KieBuilder;
  6. import org.kie.api.builder.KieFileSystem;
  7. import org.kie.api.builder.ReleaseId;
  8. import org.kie.api.builder.model.KieBaseModel;
  9. import org.kie.api.builder.model.KieModuleModel;
  10. import org.kie.api.builder.model.KieSessionModel;
  11. import org.kie.api.conf.EqualityBehaviorOption;
  12. import org.kie.api.conf.EventProcessingOption;
  13.  
  14. import java.io.IOException;
  15.  
  16.  
  17.  
  18. /**
  19.  * 动态生成kjar
  20.  * @author jie01.zhu
  21.  * @DateTime 2018/3/19 22:14
  22.  */
  23. public class DroolsUtils {
  24.  
  25. 	/**
  26. 	 * 创建默认的kbase和stateful的kiesession
  27. 	 *
  28. 	 * @param ks
  29. 	 * @param isdefault
  30. 	 * @return
  31. 	 */
  32. 	private static KieFileSystem createKieFileSystemWithKProject(KieServices ks, boolean isdefault) {
  33. 		KieModuleModel kproj = ks.newKieModuleModel();
  34. 		KieBaseModel kieBaseModel1 = kproj.newKieBaseModel("KBase").setDefault(isdefault)
  35. 				.setEqualsBehavior(EqualityBehaviorOption.EQUALITY)
  36. 				.setEventProcessingMode(EventProcessingOption.STREAM);
  37. 		// Configure the KieSession.
  38. 		kieBaseModel1.newKieSessionModel("KSession").setDefault(isdefault)
  39. 				.setType(KieSessionModel.KieSessionType.STATEFUL);
  40. 		KieFileSystem kfs = ks.newKieFileSystem();
  41. 		kfs.writeKModuleXML(kproj.toXML());
  42. 		return kfs;
  43. 	}
  44.  
  45. 	/**
  46. 	 * 创建kjar的pom
  47. 	 *
  48. 	 * @param releaseId
  49. 	 * @param dependencies
  50. 	 * @return
  51. 	 */
  52. 	private static String getPom(ReleaseId releaseId, ReleaseId... dependencies) {
  53. 		String pom = "<?xml version="1.0" encoding="UTF-8"?>
"
  54. 				+ "<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
"
  55. 				+ "         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
"
  56. 				+ "  <modelVersion>4.0.0</modelVersion>
" + "
" + "  <groupId>" + releaseId.getGroupId()
  57. 				+ "</groupId>
" + "  <artifactId>" + releaseId.getArtifactId() + "</artifactId>
" + "  <version>"
  58. 				+ releaseId.getVersion() + "</version>
" + "
";
  59. 		if (dependencies != null && dependencies.length > 0) {
  60. 			pom += "<dependencies>
";
  61. 			for (ReleaseId dep : dependencies) {
  62. 				pom += "<dependency>
";
  63. 				pom += "  <groupId>" + dep.getGroupId() + "</groupId>
";
  64. 				pom += "  <artifactId>" + dep.getArtifactId() + "</artifactId>
";
  65. 				pom += "  <version>" + dep.getVersion() + "</version>
";
  66. 				pom += "</dependency>
";
  67. 			}
  68. 			pom += "</dependencies>
";
  69. 		}
  70. 		pom += "</project>";
  71. 		return pom;
  72. 	}
  73.  
  74. 	/**
  75. 	 * 初始化一个kjar：把原有的drl包含进新建的kjar中
  76. 	 *
  77. 	 * @param ks
  78. 	 * @param releaseId
  79. 	 * @return
  80. 	 * @throws IOException
  81. 	 */
  82. 	public static InternalKieModule initKieJar(KieServices ks, ReleaseId releaseId) throws IOException {
  83. 		KieFileSystem kfs = createKieFileSystemWithKProject(ks, true);
  84. 		kfs.writePomXML(getPom(releaseId));
  85. 		KieBuilder kieBuilder = ks.newKieBuilder(kfs);
  86. 		if (!kieBuilder.buildAll().getResults().getMessages().isEmpty()) {
  87. 			throw new IllegalStateException("Error creating KieBuilder.");
  88. 		}
  89. 		return (InternalKieModule) kieBuilder.getKieModule();
  90. 	}
  91.  
  92. 	public static InternalKieModule createKieJar(KieServices ks, ReleaseId releaseId, DroolsResource droolsResource) {
  93. 		KieFileSystem kfs = createKieFileSystemWithKProject(ks, true);
  94. 		kfs.writePomXML(getPom(releaseId));
  95. 		kfs.write("src/main/resources/" + droolsResource.getTargetResourceName(), droolsResource.getResource());
  96.  
  97. 		KieBuilder kieBuilder = ks.newKieBuilder(kfs);
  98. 		if (!kieBuilder.getResults().getMessages().isEmpty()) {
  99. 			throw new IllegalStateException(
  100. 					"Error creating KieBuilder. errorMsg:" + kieBuilder.getResults().getMessages());
  101. 		}
  102. 		return (InternalKieModule) kieBuilder.getKieModule();
  103. 	}
  104.  
  105.  
  106. }

重点调用参考:

  1. String fileName = "jie-" + group + "-rules";
  2. /**
  3.  * 指定kjar包
  4.  */
  5. final ReleaseId releaseId = kieServices.newReleaseId("com.vip.jie", fileName, "1.0.0");
  6.  
  7. log.info("DroolsGetKieSession fileName:{}", fileName);
  8. log.info("[DroolsGetKieSession] drlStr:{}", drlStr);
  9. // 创建初始化的kjar
  10. InternalKieModule kJar = DroolsUtils.createKieJar(kieServices, releaseId,
  11. 		new DroolsResource(ResourceFactory.newByteArrayResource(drlStr.getBytes()),
  12. 				fileName + ".drl"));

    其次再将如何让使用者可以很灵活的接入,利用可变参数类型,将入参对象无限制传入,由规则脚本去决定入参的变化,通过此种方式可以比较好的实现业务灵活接入

如下单元测试类:

  1. package com.vip.jie.rule.service.impl;
  2.  
  3.  
  4. import com.vip.jie.rule.object.User;
  5. import com.vip.jie.rule.service.RuleManager;
  6. import lombok.extern.slf4j.Slf4j;
  7. import org.junit.Test;
  8.  
  9. import static junit.framework.TestCase.fail;
  10.  
  11. /**
  12.  * 规则测试
  13.  *  @author jie01.zhu
  14.  *	@DateTime 2018/3/19 21:17
  15.  *
  16.  */
  17. @Slf4j
  18. public class RuleManagerImplTest {
  19.  
  20. 	private RuleManager ruleManager = new RuleManagerImpl();
  21.  
  22. 	private String getRuleContent() {
  23. 		StringBuilder stringBuilder = new StringBuilder();
  24.  
  25. 		stringBuilder.append("import com.vip.jie.rule.object.User;
");
  26. 		stringBuilder.append("rule test1 when
");
  27. 		stringBuilder.append("user : User(age==20)
");
  28. 		stringBuilder.append("then
");
  29. 		stringBuilder.append("user.setName("张三");
");
  30. 		stringBuilder.append("end
");
  31. 		return stringBuilder.toString();
  32. 	}
  33.  
  34. 	@Test
  35. 	public void executeRule1() throws Exception {
  36.  
  37. 		User user = new User();
  38. 		user.setAge(20);
  39.  
  40. 		//调用规则
  41. 		ruleManager.executeRule("test1", getRuleContent(), user);
  42. 		log.info("test result:{}", user.toString());
  43.  
  44. 		if (!"张三".equals(user.getName())) {
  45. 			fail("error rule");
  46. 		}
  47. 	}
  48.  
  49. 	@Test
  50. 	public void executeRule2() throws Exception {
  51.  
  52. 		User user = new User();
  53. 		user.setAge(21);
  54.  
  55. 		//调用规则
  56. 		ruleManager.executeRule("test1", getRuleContent(), user);
  57. 		log.info("test result:{}", user.toString());
  58.  
  59. 		if ("张三".equals(user.getName())) {
  60. 			fail("error rule");
  61. 		}
  62. 	}
  63. }

三.对应示例源代码获取方式

githup:

https://github.com/jie01/drools-demo

csdn资源下载地址:

https://download.csdn.net/download/vipshop_fin_dev/10296393


还有一些关于安全性及与spring的封装思路,作者表示还会继续完善,并还不是最终版本,有需要可以持续关注-_-!


与当前文章有关联的链接

业务框架之个性化监控方案



vipshop_ebs/朱杰

2018-03-19


原文地址：https://blog.csdn.net/vipshop_fin_dev/article/details/79618067
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原文地址：https://www.cnblogs.com/jpfss/p/12018133.html