Spring Cloud 2.x之Activiti整合規則引擎Drools
阿新 • • 發佈：2018-12-15
日常生活是由規則驅動的。紅燈停綠燈行，這是我們的交通規則；我們站著往上跳，最終還是要落下來，這是地球的引力規則。規則在生活中無處不在。軟體開發中我們也需要規則，滿足什麼規則應該進入什麼分支。如果做過風控系統，就知道風控系統裡存在非常多的規則（比如：age < 16 || age > 50 -> REJECT ）。最便捷的實現就是用 if-else 來寫，但是隨著規則的增加以及需求的變動，程式碼將變得越來越難閱讀和理解，如果再去修改這些程式碼，然後測試不夠充分的話，將產生嚴重的生產事故。這時候就要引入Drools等規則引擎了。Drools就是為了解決業務程式碼和業務規則分離的引擎。
要使用Drools規則引擎，需要先安裝安裝JBoss Drools Support外掛，這裡就不多說怎麼安裝安裝JBoss Drools Support外掛。下載地址如下：
https://download.jboss.org/drools/release/7.3.0.Final/droolsjbpm-tools-distribution-7.3.0.Final.zip
1、 新建專案sc-activiti-drools，對應的pom.xml檔案如下
<?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.sc</groupId> <artifactId>sc-activiti-drools</artifactId> <version>0.0.1-SNAPSHOT</version> <name>sc-activiti-drools</name> <!-- FIXME change it to the project's website --> <url>http://www.example.com</url> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <maven.compiler.source>1.8</maven.compiler.source> <maven.compiler.target>1.8</maven.compiler.target> </properties> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>2.0.4.RELEASE</version> </parent> <dependencyManagement> <dependencies> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-dependencies</artifactId> <version>Finchley.RELEASE</version> <type>pom</type> <scope>import</scope> </dependency> </dependencies> </dependencyManagement> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.activiti</groupId> <artifactId>activiti-engine</artifactId> <version>6.0.0</version> </dependency> <dependency> <groupId>org.activiti</groupId> <artifactId>activiti-spring</artifactId> <version>6.0.0</version> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <scope>runtime</scope> </dependency> <dependency> <groupId>org.drools</groupId> <artifactId>drools-core</artifactId> <version>7.0.0.Final</version> </dependency> <dependency> <groupId>org.drools</groupId> <artifactId>drools-compiler</artifactId> <version>7.0.0.Final</version> </dependency> <dependency> <groupId>org.drools</groupId> <artifactId>knowledge-api</artifactId> <version>6.5.0.Final</version> </dependency> </dependencies> <build> <pluginManagement><!-- lock down plugins versions to avoid using Maven defaults (may be moved to parent pom) --> <plugins> <plugin> <artifactId>maven-clean-plugin</artifactId> <version>3.0.0</version> </plugin> <!-- see http://maven.apache.org/ref/current/maven-core/default-bindings.html#Plugin_bindings_for_jar_packaging --> <plugin> <artifactId>maven-resources-plugin</artifactId> <version>3.0.2</version> </plugin> <plugin> <artifactId>maven-compiler-plugin</artifactId> <version>3.7.0</version> </plugin> <plugin> <artifactId>maven-surefire-plugin</artifactId> <version>2.20.1</version> </plugin> <plugin> <artifactId>maven-jar-plugin</artifactId> <version>3.0.2</version> </plugin> <plugin> <artifactId>maven-install-plugin</artifactId> <version>2.5.2</version> </plugin> <plugin> <artifactId>maven-deploy-plugin</artifactId> <version>2.8.2</version> </plugin> </plugins> </pluginManagement> </build>
2、新建spring配置檔案application.yml
spring: datasource: driver-class-name: com.mysql.jdbc.Driver url: jdbc:mysql://127.0.0.1:3306/sc?characterEncoding=utf8&useSSL=true username: root password: root activiti: check-process-definitions: false #自動部署驗證設定:true-開啟（預設）、false-關閉 jpa: properties: hibernate: hbm2ddl: auto: update show-sql: true server: port: 8081 context-path: / session: timeout: 10 tomcat: uri-encoding: UTF-8
3、新建activiti對應的配置檔案activiti.cfg.xml
<?xml version="1.0" encoding="UTF-8"?>
<bean id="dataSource" class="org.springframework.jdbc.datasource.SimpleDriverDataSource">
<property name="driverClass" value="com.mysql.jdbc.Driver" />
<property name="url" value="jdbc:mysql://localhost:3306/act?useUnicode=true&characterEncoding=UTF-8" />
<property name="username" value="root" />
<property name="password" value="root" />
</bean>
<bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
<property name="dataSource" ref="dataSource" />
</bean>
<bean id="processEngineConfiguration" class="org.activiti.spring.SpringProcessEngineConfiguration">
<property name="dataSource" ref="dataSource" />
<property name="transactionManager" ref="transactionManager" />
<property name="databaseSchemaUpdate" value="true" />
<property name="customPostDeployers">
<list>
<bean class="org.activiti.engine.impl.rules.RulesDeployer" />
</list>
</property>
<!--
<property name="deploymentResources" value="classpath*:/bpmn/*.bpmn" />
-->
</bean>
<bean id="processEngine" class="org.activiti.spring.ProcessEngineFactoryBean">
<property name="processEngineConfiguration" ref="processEngineConfiguration" />
</bean>
<bean id="repositoryService" factory-bean="processEngine" factory-method="getRepositoryService" />
<bean id="runtimeService" factory-bean="processEngine" factory-method="getRuntimeService" />
<bean id="taskService" factory-bean="processEngine" factory-method="getTaskService" />
<bean id="historyService" factory-bean="processEngine" factory-method="getHistoryService" />
<bean id="managementService" factory-bean="processEngine" factory-method="getManagementService" />
4、新建請假流程對應的bpmn檔案如下
<?xml version="1.0" encoding="UTF-8"?>
<definitions xmlns="http://www.omg.org/spec/BPMN/20100524/MODEL"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema"
xmlns:activiti="http://activiti.org/bpmn" xmlns:bpmndi="http://www.omg.org/spec/BPMN/20100524/DI"
xmlns:omgdc="http://www.omg.org/spec/DD/20100524/DC" xmlns:omgdi="http://www.omg.org/spec/DD/20100524/DI"
typeLanguage="http://www.w3.org/2001/XMLSchema" expressionLanguage="http://www.w3.org/1999/XPath"
targetNamespace="http://www.activiti.org/test">
<process id="leave" name="請假審批" isExecutable="true">
<startEvent id="startevent1" name="Start"></startEvent>
<endEvent id="endevent1" name="End"></endEvent>
<userTask id="usertask1" name="部門經理審批"></userTask>
<businessRuleTask id="businessruletask1" name="天數判斷" activiti:ruleVariablesInput="${leave}" activiti:rules="leave1,leave2" activiti:resultVariable="reason"></businessRuleTask>
<serviceTask id="servicetask1" name="獲取變數" activiti:class="sc.ad.service.DroolsService"></serviceTask>
<userTask id="usertask2" name="HR審批"></userTask>
<sequenceFlow id="flow1" sourceRef="startevent1" targetRef="usertask1"></sequenceFlow>
<sequenceFlow id="flow2" sourceRef="usertask1" targetRef="businessruletask1"></sequenceFlow>
<sequenceFlow id="flow3" sourceRef="businessruletask1" targetRef="servicetask1"></sequenceFlow>
<userTask id="usertask3" name="總經理審批"></userTask>
<sequenceFlow id="flow4" sourceRef="servicetask1" targetRef="usertask3">
<conditionExpression xsi:type="tFormalExpression"><![CDATA[${reason[0].total >= 10}]]></conditionExpression>
</sequenceFlow>
<sequenceFlow id="flow5" sourceRef="servicetask1" targetRef="usertask2">
<conditionExpression xsi:type="tFormalExpression"><![CDATA[${reason[0].total < 10}]]></conditionExpression>
</sequenceFlow>
<sequenceFlow id="flow6" sourceRef="usertask3" targetRef="usertask2"></sequenceFlow>
<sequenceFlow id="flow7" sourceRef="usertask2" targetRef="endevent1"></sequenceFlow>
</process>
</definitions>
bpmn檔案對應的圖如下
5、新建規則檔案leave.drl
package sc.ad;
import sc.ad.model.Leave;
rule "leave1"
when
u : Leave(day < 3);
then
u.setTotal(u.getDay() + 2);
end
rule "leave2"
when
u : Leave(day >= 3);
then
u.setTotal(u.getDay() + 5);
end
對應的圖如下
6、新建springboot啟動類檔案
package sc.ad;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.ImportResource;
@SpringBootApplication
@ImportResource("activiti.cfg.xml")
public class ActivitiDroolsApp {
public static void main(String[] args)
{
SpringApplication.run(ActivitiDroolsApp.class, args);
}
}
7、新建一個controller，用來發起請假請求
package sc.ad.controller;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.activiti.engine.RepositoryService;
import org.activiti.engine.RuntimeService;
import org.activiti.engine.TaskService;
import org.activiti.engine.repository.Deployment;
import org.activiti.engine.repository.DeploymentBuilder;
import org.activiti.engine.repository.ProcessDefinition;
import org.activiti.engine.runtime.ProcessInstance;
import org.activiti.engine.task.Task;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import sc.ad.model.Leave;
@RestController
public class ADController {
@Autowired
private RepositoryService repositoryService;
@Autowired
private RuntimeService runtimeService;
@Autowired
private TaskService taskService;
// @RequestMapping("/ad")
// public void ad() {
//
// // 根據bpmn檔案部署流程
// Deployment deployment = repositoryService.createDeployment()
// .addClasspathResource("holiday.bpmn").deploy();
// // 獲取流程定義
// ProcessDefinition processDefinition = repositoryService
// .createProcessDefinitionQuery()
// .deploymentId(deployment.getId()).singleResult();
// // 啟動流程定義，返回流程例項
// ProcessInstance pi = runtimeService
// .startProcessInstanceById(processDefinition.getId());
// String processId = pi.getId();
// System.out.println("流程建立成功，當前流程例項ID：" + processId);
//
// Task task = taskService.createTaskQuery().processInstanceId(processId)
// .singleResult();
// System.out.println("第一次執行前，任務名稱：" + task.getName());
// taskService.complete(task.getId());
//
// task = taskService.createTaskQuery().processInstanceId(processId)
// .singleResult();
// System.out.println("第二次執行前，任務名稱：" + task.getName());
// taskService.complete(task.getId());
//
// task = taskService.createTaskQuery().processInstanceId(processId)
// .singleResult();
// System.out.println("task為null，任務執行完畢：" + task);
// }
@RequestMapping("/drl")
public void drl() {
/**
* 注意這裡：必須要把drl檔案一起deploy
*/
DeploymentBuilder deploy = repositoryService.createDeployment();
deploy.addClasspathResource("leave.bpmn").addClasspathResource("leave.drl");
deploy.deploy();
ProcessInstance pi = runtimeService.startProcessInstanceByKey("leave");
Map<String, Object> vars = new HashMap<String, Object>();
vars.put("leave", new Leave("白展堂", 12));
/**
* 當前任務
*/
List<Task> tasks = taskService.createTaskQuery().processInstanceId(pi.getId()).list();
for(Task task : tasks)
{
System.out.println(task.getId() + " , " + task.getName());
taskService.complete(task.getId(), vars);
}
/**
* 下一步任務
*/
tasks = taskService.createTaskQuery().processInstanceId(pi.getId()).list();
for(Task task : tasks)
{
System.out.println(task.getId() + " , " + task.getName());
}
}
}
8、啟動並驗證規則是否生效
從日誌中看啟動成功
訪問http://127.0.0.1:8081/drl後，再次檢視日誌：
把修改controller的如下程式碼
vars.put("leave", new Leave("白展堂", 12));
改成
vars.put(“leave”, new Leave(“喬峰”, 2));
可以看到規則檔案的規則已經生效：
