关于drools的简单笔记

一、什么是drools

简单回答就是把代码变成配置文件，原来写在java类里的东西，现在全部帮到配置文件里。

二、配置文件是什么

配置文件可以是drl结尾的文件，也可以是excel表，现在比较流行的是使用excel表。

三、drools如何调用

首先读取excel表的配置文件，这个叫做初始化。

初始化完成后，需要相应的实体bean用来传递参数供规则判断

如果是drl规则的写法和java类型

如果是excel那就简单的多，可以百度drools excel模板

需要注意的是，如果要使用drools一定要首先初始化，即加载规则。

另外还可以配置刷新规则，即重新加载配置文件。

下面是使用drl作为配置文件的源码。

bean PointDomain.java

package com.drools.demo.point;

/**
* 积分计算对象
* @author quzishen
*/
public class PointDomain {
// 用户名
private String userName;
// 是否当日生日
private boolean birthDay;
// 增加积分数目
private long point;
// 当月购物次数
private int buyNums;
// 当月退货次数
private int backNums;
// 当月购物总金额
private double buyMoney;
// 当月退货总金额
private double backMondy;
// 当月信用卡还款次数
private int billThisMonth;

/**
* 记录积分发送流水，防止重复发放
* @param userName 用户名
* @param type 积分发放类型
*/
public void recordPointLog(String userName, String type){
System.out.println("增加对"+userName+"的类型为"+type+"的积分操作记录.");
}

public String getUserName() {
return userName;
}

public void setUserName(String userName) {
this.userName = userName;
}

public boolean isBirthDay() {
return birthDay;
}

public void setBirthDay(boolean birthDay) {
this.birthDay = birthDay;
}

public long getPoint() {
return point;
}

public void setPoint(long point) {
this.point = point;
}

public int getBuyNums() {
return buyNums;
}

public void setBuyNums(int buyNums) {
this.buyNums = buyNums;
}

public int getBackNums() {
return backNums;
}

public void setBackNums(int backNums) {
this.backNums = backNums;
}

public double getBuyMoney() {
return buyMoney;
}

public void setBuyMoney(double buyMoney) {
this.buyMoney = buyMoney;
}

public double getBackMondy() {
return backMondy;
}

public void setBackMondy(double backMondy) {
this.backMondy = backMondy;
}

public int getBillThisMonth() {
return billThisMonth;
}

public void setBillThisMonth(int billThisMonth) {
this.billThisMonth = billThisMonth;
}

}


PointRuleEngine.java
package com.drools.demo.point;

/**
* 规则接口
* @author quzishen
*/
public interface PointRuleEngine {

/**
* 初始化规则引擎
*/
public void initEngine();

/**
* 刷新规则引擎中的规则
*/
public void refreshEnginRule();

/**
* 执行规则引擎
* @param pointDomain 积分Fact
*/
public void executeRuleEngine(final PointDomain pointDomain);
}


PointRuleEngineImpl.java
package com.drools.demo.point;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.io.Reader;
import java.util.ArrayList;
import java.util.List;

import org.drools.RuleBase;
import org.drools.StatefulSession;
import org.drools.compiler.DroolsParserException;
import org.drools.compiler.PackageBuilder;
import org.drools.spi.Activation;

/**
* 规则接口实现类
* @author quzishen
*/
public class PointRuleEngineImpl implements PointRuleEngine {
private RuleBase ruleBase;

/* (non-Javadoc)
* @see com.drools.demo.point.PointRuleEngine#initEngine()
*/
public void initEngine() {
// 设置时间格式
System.setProperty("drools.dateformat", "yyyy-MM-dd HH:mm:ss");
ruleBase = RuleBaseFacatory.getRuleBase();
try {
PackageBuilder backageBuilder = getPackageBuilderFromDrlFile();
ruleBase.addPackages(backageBuilder.getPackages());
} catch (DroolsParserException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
}
}

/* (non-Javadoc)
* @see com.drools.demo.point.PointRuleEngine#refreshEnginRule()
*/
public void refreshEnginRule() {
ruleBase = RuleBaseFacatory.getRuleBase();
org.drools.rule.Package[] packages = ruleBase.getPackages();
for(org.drools.rule.Package pg : packages) {
ruleBase.removePackage(pg.getName());
}

initEngine();
}

/* (non-Javadoc)
* @see com.drools.demo.point.PointRuleEngine#executeRuleEngine(com.drools.demo.point.PointDomain)
*/
public void executeRuleEngine(final PointDomain pointDomain) {
if(null == ruleBase.getPackages() || 0 == ruleBase.getPackages().length) {
return;
}

StatefulSession statefulSession = ruleBase.newStatefulSession();
statefulSession.insert(pointDomain);

// fire
statefulSession.fireAllRules(new org.drools.spi.AgendaFilter() {
public boolean accept(Activation activation) {
return !activation.getRule().getName().contains("_test");
}
});

statefulSession.dispose();
}

/**
* 从Drl规则文件中读取规则
* @return
* @throws Exception
*/
private PackageBuilder getPackageBuilderFromDrlFile() throws Exception {
// 获取测试脚本文件
List<String> drlFilePath = getTestDrlFile();
// 装载测试脚本文件
List<Reader> readers = readRuleFromDrlFile(drlFilePath);

PackageBuilder backageBuilder = new PackageBuilder();
for (Reader r : readers) {
backageBuilder.addPackageFromDrl(r);
}

// 检查脚本是否有问题
if(backageBuilder.hasErrors()) {
throw new Exception(backageBuilder.getErrors().toString());
}

return backageBuilder;
}

/**
* @param drlFilePath 脚本文件路径
* @return
* @throws FileNotFoundException
*/
private List<Reader> readRuleFromDrlFile(List<String> drlFilePath) throws FileNotFoundException {
if (null == drlFilePath || 0 == drlFilePath.size()) {
return null;
}

List<Reader> readers = new ArrayList<Reader>();

for (String ruleFilePath : drlFilePath) {
readers.add(new FileReader(new File(ruleFilePath)));
}

return readers;
}

/**
* 获取测试规则文件
*
* @return
*/
private List<String> getTestDrlFile() {
List<String> drlFilePath = new ArrayList<String>();
drlFilePath
.add("D:/0_eclipse/DroolsDemo/src/com/drools/demo/point/addpoint.drl");
drlFilePath
.add("D:/0_eclipse/DroolsDemo/src/com/drools/demo/point/subpoint.drl");

return drlFilePath;
}
}


RuleBaseFacatory.java
package com.drools.demo.point;

import org.drools.RuleBase;
import org.drools.RuleBaseFactory;

/**
* RuleBaseFacatory 单实例RuleBase生成工具
* @author quzishen
*/
public class RuleBaseFacatory {
private static RuleBase ruleBase;

public static RuleBase getRuleBase(){
return null != ruleBase ? ruleBase : RuleBaseFactory.newRuleBase();
}
}


Test.java
package com.drools.demo.point;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;

public class Test {

/**
* @param args
* @throws IOException
*/
public static void main(String[] args) throws IOException {
PointRuleEngine pointRuleEngine = new PointRuleEngineImpl();
while(true){
InputStream is = System.in;
BufferedReader br = new BufferedReader(new InputStreamReader(is));
String input = br.readLine();

if(null != input && "s".equals(input)){
System.out.println("初始化规则引擎...");
pointRuleEngine.initEngine();
System.out.println("初始化规则引擎结束.");
}else if("e".equals(input)){
final PointDomain pointDomain = new PointDomain();
pointDomain.setUserName("hello kity");
pointDomain.setBackMondy(100d);
pointDomain.setBuyMoney(500d);
pointDomain.setBackNums(1);
pointDomain.setBuyNums(5);
pointDomain.setBillThisMonth(5);
pointDomain.setBirthDay(true);
pointDomain.setPoint(0l);

pointRuleEngine.executeRuleEngine(pointDomain);

System.out.println("执行完毕BillThisMonth："+pointDomain.getBillThisMonth());
System.out.println("执行完毕BuyMoney："+pointDomain.getBuyMoney());
System.out.println("执行完毕BuyNums："+pointDomain.getBuyNums());

System.out.println("执行完毕规则引擎决定发送积分："+pointDomain.getPoint());
} else if("r".equals(input)){
System.out.println("刷新规则文件...");
pointRuleEngine.refreshEnginRule();
System.out.println("刷新规则文件结束.");
}
}
}

}


addpoint.drl
package com.drools.demo.point

import com.drools.demo.point.PointDomain;

rule birthdayPoint
// 过生日，则加10分，并且将当月交易比数翻倍后再计算积分
salience 100
//salience 优先级，数值越大越先执行，这个可以控制规则的执行顺序。
lock-on-active true
when
$pointDomain : PointDomain(birthDay == true)
then
$pointDomain.setPoint($pointDomain.getPoint()+10);
$pointDomain.setBuyNums($pointDomain.getBuyNums()*2);
$pointDomain.setBuyMoney($pointDomain.getBuyMoney()*2);
$pointDomain.setBillThisMonth($pointDomain.getBillThisMonth()*2);

$pointDomain.recordPointLog($pointDomain.getUserName(),"birthdayPoint");
end

rule billThisMonthPoint
// 2011-01-08 - 2011-08-08每月信用卡还款3次以上，每满3笔赠送30分
salience 99
lock-on-active true
date-effective "2011-01-08 23:59:59"
date-expires "2011-08-08 23:59:59"
when
$pointDomain : PointDomain(billThisMonth >= 3)
then
$pointDomain.setPoint($pointDomain.getPoint()+$pointDomain.getBillThisMonth()/3*30);
$pointDomain.recordPointLog($pointDomain.getUserName(),"billThisMonthPoint");
end

rule buyMoneyPoint
// 当月购物总金额100以上，每100元赠送10分
salience 98
lock-on-active true
when
$pointDomain : PointDomain(buyMoney >= 100)
then
$pointDomain.setPoint($pointDomain.getPoint()+ (int)$pointDomain.getBuyMoney()/100 * 10);
$pointDomain.recordPointLog($pointDomain.getUserName(),"buyMoneyPoint");
end

rule buyNumsPoint
// 当月购物次数5次以上，每五次赠送50分
salience 97
lock-on-active true
when
$pointDomain : PointDomain(buyNums >= 5)
then
$pointDomain.setPoint($pointDomain.getPoint()+$pointDomain.getBuyNums()/5 * 50);
$pointDomain.recordPointLog($pointDomain.getUserName(),"buyNumsPoint");
end

rule allFitPoint
// 特别的，如果全部满足了要求，则额外奖励100分
salience 96
lock-on-active true
when
$pointDomain:PointDomain(buyNums >= 5 && billThisMonth >= 3 && buyMoney >= 100)
then
$pointDomain.setPoint($pointDomain.getPoint()+ 100);
$pointDomain.recordPointLog($pointDomain.getUserName(),"allFitPoint");
end

subpoint.drl
package com.drools.demo.point

import com.drools.demo.point.PointDomain;

rule subBackNumsPoint
// 发生退货，扣减10分
salience 10
lock-on-active true
when
$pointDomain : PointDomain(backNums >= 1)
then
$pointDomain.setPoint($pointDomain.getPoint()-10);
$pointDomain.recordPointLog($pointDomain.getUserName(),"subBackNumsPoint");
end

rule subBackMondyPoint
// 退货金额大于100，扣减100分
salience 9
lock-on-active true
when
$pointDomain : PointDomain(backMondy >= 100)
then
$pointDomain.setPoint($pointDomain.getPoint()-10);
$pointDomain.recordPointLog($pointDomain.getUserName(),"subBackMondyPoint");
end