南宁商城网站建设,做网站页面代码,网线制作顺序图解,做家居网站设计规则引擎适用于有复杂多变的规则#xff0c;如商品满减、积分赠送、考勤规则等 一、引入maven依赖 dependencygroupIdorg.drools/groupIdartifactIddrools-core/artifactIdversion7.13.0.Final/version
/depende…规则引擎适用于有复杂多变的规则如商品满减、积分赠送、考勤规则等 一、引入maven依赖 dependencygroupIdorg.drools/groupIdartifactIddrools-core/artifactIdversion7.13.0.Final/version
/dependency
dependencygroupIdorg.drools/groupIdartifactIddrools-compiler/artifactIdversion7.13.0.Final/version
/dependency二、drools有两种执行方式第一种是基于kmodule.xml、drl配置文件第二种是动态读取规则 基于kmodule方式 1创建Factdrools中的Fact即是java中的普通的bean用于传递参数 package com.beyond.odc.entity;/*** Fact java bean* author Hejinsheng*/
public class Message {private String message;private String result;private int status;public String getMessage() {return this.message;}public void setMessage(String message) {this.message message;}public int getStatus() {return this.status;}public void setStatus(int status) {this.status status;}public String getResult() {return result;}public void setResult(String result) {this.result result;}
}2在resources/META-INF下创建kmodule.xml文件内容如下 ?xml version1.0 encodingUTF-8?
kmodule xmlnshttp://jboss.org/kie/6.0.0/kmodulekbase namerules packagesrulesksession nameksession-rules//kbase
/kmodule3在resources/rules文件夹下创建规则描述文件rules.drl内容如下 package rulesimport com.beyond.odc.entity.Message;rule hellono-loop truelock-on-active truewhen$message:Message(status0)thenSystem.out.println(消息$message.getMessage());$message.setResult(hello 响应的消息);update($message)
endrule byebyeno-loop truelock-on-active truewhen$message:Message(status1)thenSystem.out.println(消息$message.getMessage());$message.setResult(byebye 响应的消息);update($message)
end4编写测试文件 public static void main(String[] args) {try {KieSession kSession KieContainerFactory.getKieContainer().newKieSession(ksession-rules);Message message new Message();message.setMessage(hello); // 对应drl文件中的rule name表示要执行的规则message.setStatus(0); // 取message中的某个字段用户规则文件中的判断是否执行代码块kSession.insert(message); // 将message作为传递的参数传入drools执行kSession.fireAllRules(); // 加载规则System.out.println(从drools中接收到的消息message.getResult()); // drools中如果有参数响应可以通过字段获取} catch (Throwable t) {t.printStackTrace();}
} //KieContainerFactory代码片段
public class KieContainerFactory {private static KieContainer kieContainer;public static KieContainer getKieContainer() {if(kieContainer null){// load up the knowledge baseKieServices ks KieServices.Factory.get();KieContainer kContainer ks.getKieClasspathContainer();kieContainer kContainer;}return kieContainer;}
}5执行结果说明代码已经执行到drools文件中具体的业务逻辑可以在then后的代码块中实现 进来了消息hello
从drools中接收到的消息hello 响应的消息三、动态方式执行 一般指从数据库或者远程获取的规则描述信息进行规则执行。动态方式不需要kmodule.xml和drl文件执行上更加简单 public static void execFromDB(){KieSession kSession null;try {// 实际情况从数据库根据code查规则这里模拟写死String rule package rules\n \n import com.beyond.odc.entity.Message;\n \n rule \hello\\n no-loop true\n lock-on-active true\n when\n $message:Message(status0)\n then\n System.out.println(\动态执行消息\$message.getMessage());\n $message.setResult(\hello 响应的消息\);\n update($message)\n end\n \n rule \byebye\\n no-loop true\n lock-on-active true\n when\n $message:Message(status1)\n then\n System.out.println(\动态执行消息\$message.getMessage());\n $message.setResult(\byebye 响应的消息\);\n update($message)\n end;KnowledgeBuilder kb KnowledgeBuilderFactory.newKnowledgeBuilder();kb.add(ResourceFactory.newByteArrayResource(rule.getBytes(utf-8)), ResourceType.DRL);// 检查规则正确性KnowledgeBuilderErrors errors kb.getErrors();for (KnowledgeBuilderError error : errors) {System.out.println(规则文件正确性有误{} error);}InternalKnowledgeBase kBase KnowledgeBaseFactory.newKnowledgeBase();kBase.addPackages(kb.getKnowledgePackages());// 执行规则kSession kBase.newKieSession();// factMessage fact new Message();fact.setMessage(byebye);fact.setStatus(1);kSession.insert(fact);kSession.fireAllRules();System.out.println(从drools规则中接收到的消息fact.getResult());} catch (Exception e) {System.out.println(规则执行异常{}e);} finally {if (null ! kSession)kSession.dispose();}}执行结果如下 动态执行消息byebye
从drools规则中接收到的消息byebye 响应的消息转载于:https://www.cnblogs.com/half-two-feet/p/9876684.html
