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規則引擎drools封裝

一.前言

    網上規則引擎drools介紹很多,并且有很多細緻的說明,作者也不敢托大說自己的好用,但作者經過2個項目使用過規則引擎後,自己對規則引擎的了解并進行封裝,對規則内容及如何使用,有自己的一番實踐,并提供源代碼,供大家參考

二.設計思路及具體代碼

    首先我希望是輕量級的使用drools,不希望使用太過複雜的架構,以這種思路入手,就可以與任何項目輕易融入,這樣就需要能夠将drools規則的來源,從規則檔案(drl)中可以從maven和自己的資料庫中擷取,腳本是動态的,配合drools6.5支援通過maven接入的規則的API,就可以做到從任何處擷取規則内容

一個工具類DroolsUtils

     
  1.  package com.vip.jie.rule.util;       
    2.           
  2.  import org.drools.compiler.kie.builder.impl.InternalKieModule;       
    3.       
  3.  import org.kie.api.KieServices;       
    4.       
  4.  import org.kie.api.builder.KieBuilder;       
    5.       
  5.  import org.kie.api.builder.KieFileSystem;       
    6.       
  6.  import org.kie.api.builder.ReleaseId;       
    7.       
  7.  import org.kie.api.builder.model.KieBaseModel;       
    8.       
  8.  import org.kie.api.builder.model.KieModuleModel;       
    9.       
  9.  import org.kie.api.builder.model.KieSessionModel;       
    10.       
  10.  import org.kie.api.conf.EqualityBehaviorOption;       
    11.       
  11.  import org.kie.api.conf.EventProcessingOption;       
    12.           
  12.  import java.io.IOException;       
    13.                   
  13.  /**       
    14.       
  14.  * 動态生成kjar       
    15.       
  15.  * @author jie01.zhu       
    16.       
  16.  * @DateTime 2018/3/19 22:14       
    17.       
  17.  */       
    18.       
  18.  public class DroolsUtils {       
    19.           
  19.  /**       
    20.       
  20.  * 建立預設的kbase和stateful的kiesession       
    21.       
  21.  *       
    22.       
  22.  * @param ks       
    23.       
  23.  * @param isdefault       
    24.       
  24.  * @return       
    25.       
  25.  */       
    26.       
  26.  private static KieFileSystem createKieFileSystemWithKProject(KieServices ks, boolean isdefault) {       
    27.       
  27.  KieModuleModel kproj = ks.newKieModuleModel();       
    28.       
  28.  KieBaseModel kieBaseModel1 = kproj.newKieBaseModel("KBase").setDefault(isdefault)       
    29.       
  29.  .setEqualsBehavior(EqualityBehaviorOption.EQUALITY)       
    30.       
  30.  .setEventProcessingMode(EventProcessingOption.STREAM);       
    31.       
  31.  // Configure the KieSession.       
    32.       
  32.  kieBaseModel1.newKieSessionModel("KSession").setDefault(isdefault)       
    33.       
  33.  .setType(KieSessionModel.KieSessionType.STATEFUL);       
    34.       
  34.  KieFileSystem kfs = ks.newKieFileSystem();       
    35.       
  35.  kfs.writeKModuleXML(kproj.toXML());       
    36.       
  36.  return kfs;       
    37.       
  37.  }       
    38.           
  38.  /**       
    39.       
  39.  * 建立kjar的pom       
    40.       
  40.  *       
    41.       
  41.  * @param releaseId       
    42.       
  42.  * @param dependencies       
    43.       
  43.  * @return       
    44.       
  44.  */       
    45.       
  45.  private static String getPom(ReleaseId releaseId, ReleaseId... dependencies) {       
    46.       
  46.  String pom = "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n"       
    47.       
  47.  + "<project xmlns=\"http://maven.apache.org/POM/4.0.0\" xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\"\n"       
    48.       
  48.  + "         xsi:schemaLocation=\"http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd\">\n"       
    49.       
  49.  + "  <modelVersion>4.0.0</modelVersion>\n" + "\n" + "  <groupId>" + releaseId.getGroupId()       
    50.       
  50.  + "</groupId>\n" + "  <artifactId>" + releaseId.getArtifactId() + "</artifactId>\n" + "  <version>"       
    51.       
  51.  + releaseId.getVersion() + "</version>\n" + "\n";       
    52.       
  52.  if (dependencies != null && dependencies.length > 0) {       
    53.       
  53.  pom += "<dependencies>\n";       
    54.       
  54.  for (ReleaseId dep : dependencies) {       
    55.       
  55.  pom += "<dependency>\n";       
    56.       
  56.  pom += "  <groupId>" + dep.getGroupId() + "</groupId>\n";       
    57.       
  57.  pom += "  <artifactId>" + dep.getArtifactId() + "</artifactId>\n";       
    58.       
  58.  pom += "  <version>" + dep.getVersion() + "</version>\n";       
    59.       
  59.  pom += "</dependency>\n";       
    60.       
  60.  }       
    61.       
  61.  pom += "</dependencies>\n";       
    62.       
  62.  }       
    63.       
  63.  pom += "</project>";       
    64.       
  64.  return pom;       
    65.       
  65.  }       
    66.           
  66.  /**       
    67.       
  67.  * 初始化一個kjar：把原有的drl包含進建立的kjar中       
    68.       
  68.  *       
    69.       
  69.  * @param ks       
    70.       
  70.  * @param releaseId       
    71.       
  71.  * @return       
    72.       
  72.  * @throws IOException       
    73.       
  73.  */       
    74.       
  74.  public static InternalKieModule initKieJar(KieServices ks, ReleaseId releaseId) throws IOException {       
    75.       
  75.  KieFileSystem kfs = createKieFileSystemWithKProject(ks, true);       
    76.       
  76.  kfs.writePomXML(getPom(releaseId));       
    77.       
  77.  KieBuilder kieBuilder = ks.newKieBuilder(kfs);       
    78.       
  78.  if (!kieBuilder.buildAll().getResults().getMessages().isEmpty()) {       
    79.       
  79.  throw new IllegalStateException("Error creating KieBuilder.");       
    80.       
  80.  }       
    81.       
  81.  return (InternalKieModule) kieBuilder.getKieModule();       
    82.       
  82.  }       
    83.           
  83.  public static InternalKieModule createKieJar(KieServices ks, ReleaseId releaseId, DroolsResource droolsResource) {       
    84.       
  84.  KieFileSystem kfs = createKieFileSystemWithKProject(ks, true);       
    85.       
  85.  kfs.writePomXML(getPom(releaseId));       
    86.       
  86.  kfs.write("src/main/resources/" + droolsResource.getTargetResourceName(), droolsResource.getResource());       
    87.           
  87.  KieBuilder kieBuilder = ks.newKieBuilder(kfs);       
    88.       
  88.  if (!kieBuilder.getResults().getMessages().isEmpty()) {       
    89.       
  89.  throw new IllegalStateException(       
    90.       
  90.  "Error creating KieBuilder. errorMsg:" + kieBuilder.getResults().getMessages());       
    91.       
  91.  }       
    92.       
  92.  return (InternalKieModule) kieBuilder.getKieModule();       
    93.       
  93.  }       
    94.               
  94.  }       
    95.

重點調用參考:

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

    其次再将如何讓使用者可以很靈活的接入,利用可變參數類型,将入參對象無限制傳入,由規則腳本去決定入參的變化,通過此種方式可以比較好的實作業務靈活接入

如下單元測試類:

     
  1.  package com.vip.jie.rule.service.impl;       
    2.               
  2.  import com.vip.jie.rule.object.User;       
    3.       
  3.  import com.vip.jie.rule.service.RuleManager;       
    4.       
  4.  import lombok.extern.slf4j.Slf4j;       
    5.       
  5.  import org.junit.Test;       
    6.           
  6.  import static junit.framework.TestCase.fail;       
    7.           
  7.  /**       
    8.       
  8.  * 規則測試       
    9.       
  9.  *  @author jie01.zhu       
    10.       
  10.  *	@DateTime 2018/3/19 21:17       
    11.       
  11.  *       
    12.       
  12.  */       
    13.       
  13.  @Slf4j       
    14.       
  14.  public class RuleManagerImplTest {       
    15.           
  15.  private RuleManager ruleManager = new RuleManagerImpl();       
    16.           
  16.  private String getRuleContent() {       
    17.       
  17.  StringBuilder stringBuilder = new StringBuilder();       
    18.           
  18.  stringBuilder.append("import com.vip.jie.rule.object.User;\n");       
    19.       
  19.  stringBuilder.append("rule test1 when\n");       
    20.       
  20.  stringBuilder.append("user : User(age==20)\n");       
    21.       
  21.  stringBuilder.append("then\n");       
    22.       
  22.  stringBuilder.append("user.setName(\"張三\");\n");       
    23.       
  23.  stringBuilder.append("end\n");       
    24.       
  24.  return stringBuilder.toString();       
    25.       
  25.  }       
    26.           
  26.  @Test       
    27.       
  27.  public void executeRule1() throws Exception {       
    28.           
  28.  User user = new User();       
    29.       
  29.  user.setAge(20);       
    30.           
  30.  //調用規則       
    31.       
  31.  ruleManager.executeRule("test1", getRuleContent(), user);       
    32.       
  32.  log.info("test result:{}", user.toString());       
    33.           
  33.  if (!"張三".equals(user.getName())) {       
    34.       
  34.  fail("error rule");       
    35.       
  35.  }       
    36.       
  36.  }       
    37.           
  37.  @Test       
    38.       
  38.  public void executeRule2() throws Exception {       
    39.           
  39.  User user = new User();       
    40.       
  40.  user.setAge(21);       
    41.           
  41.  //調用規則       
    42.       
  42.  ruleManager.executeRule("test1", getRuleContent(), user);       
    43.       
  43.  log.info("test result:{}", user.toString());       
    44.           
  44.  if ("張三".equals(user.getName())) {       
    45.       
  45.  fail("error rule");       
    46.       
  46.  }       
    47.       
  47.  }       
    48.       
  48.  }       
    49.

三.對應示例源代碼擷取方式

githup:

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

csdn資源下載下傳位址:

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

還有一些關于安全性及與spring的封裝思路,作者表示還會繼續完善,并還不是最終版本,有需要可以持續關注-_-!

與目前文章有關聯的連結

業務架構之個性化監控方案

vipshop_ebs/朱傑

2018-03-19

原文位址：https://blog.csdn.net/vipshop_fin_dev/article/details/79618067

java經驗集錦 通用實踐 springboot drools 規則引擎 專家系統
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