java规则引擎实例_JAVA规则引擎[Drools]--实例篇
随着互联⽹应⽤的飞速发展，各种业务需求也应运⽽⽣，对于不断变更和⾰新的业务规则⽽⾔，项⽬的开发就很有必要把规则部分独⽴提取出来，此时Drools的价值就得到了体现。废话不多说，看⼀个简单的例⼦。
这⾥举⼀个⼿机话费的例⼦。
⼀、定义规则：
⾸先要分析⾃⼰的业务逻辑，根据业务⽽制定出不同的规则，这⾥我们假设有3个规则。
1、对于新开户的⼿机⽤户送20元话费。
2、在2014年10⽉到12期间充值的⽤户，不论⾦额多少充值满3次就赠送5元话费。
3、当⽉充值⾦额达到100以上，每达到⼀次赠送话费10元。
take out
⼆、创建Fact对象：
分析这些规则，并把他们抽象成⼀个Fact对象。
drools;
import java.util.UUID;
/**
* EntityRule-Model
* @author Candy
*
*/
public class EntityRule {
private String urname;
/** Whether for new account. */
private boolean account;
/
** The number of add. */
private int addtime;
/** The sum of the current account. */
private double currentmoney;
/** The totail amount added. */
private double totailaddmoney;
/**
* Record the rial number of the operation.
* @param urname
* @param currentmoney
*/孤独患者英文
public void getSerialnumber(String urname,double currentmoney){
System.out.println("Account："+urname+" Balance：￥"+currentmoney);
System.out.println("Serial Number："+UUID.randomUUID().toString());
}
三、定义规则引擎：
scratchpad业务和规则都整理清楚了我们就可以开始规则引擎的核⼼部分啦，这⾥我定义的是接⼝和实现类。drools;
/**
* RuleEngine-Interface
* @author Candy
*
*/
public interface RuleEngine {
/**
* Initializes the rules engine.
*/
public void init();
/**
* Refresh the rules engine.
*/
public void refresh();
/**
* Execute the rules engine.
*/
public void execute(final EntityRule entityRule);
}
drools;
import java.io.File;2013年考研复试分数线
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.RuleBa;
import org.drools.StatefulSession;
天天向上学习网import piler.DroolsParrException;
import piler.PackageBuilder;
import org.drools.rule.Package;
import org.drools.spi.Activation;
/**
* RuleEngine-Implements
* @author Candy
初次见面英语怎么说*
*/
public class RuleEngineImpl implements RuleEngine{
private RuleBa ruleBa;
/*
* (non-Javadoc)
* @drools.RuleEngine#init()
*/
@Override
public void init() {
/** Sets the system time format. */
System.tProperty("drools.dateformat", "yyyy-MM-dd HH:mm:ss"); /** Get the ba factory. */
ruleBa =RuleBa();
try {
/** Get the rule files has bean read. */
PackageBuilder backageBuilder = getPackageBuilderFile();
/** Add the package to the 'RuleBa'. */
ruleBa.Packages());
} catch (DroolsParrException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (Exception e) {globaltest
e.printStackTrace();
}
}小学课堂纪律
/*
* (non-Javadoc)
* @drools.RuleEngine#refresh()
*/
@Override
public void refresh() {
ruleBa = RuleBa();
Package[] packages = Packages();
for(Package items :packages){
}
init();
}
/*
* (non-Javadoc)
* @drools.RuleEngine#drools.EntityRule) */
@Override
public void execute(final EntityRule entityRule) {
if(null == Packages() || 0 == Packages().length) { return;
}
StatefulSession statefulSession = wStatefulSession(); statefulSession.inrt(entityRule);
statefulSession.fireAllRules(new org.drools.spi.AgendaFilter() {
public boolean accept(Activation activation) {
return !Rule().getName().contains("_test");
}
});
statefulSession.dispo();
}
/**
* Read the rule files.
* @return
* @throws Exception
*/
private PackageBuilder getPackageBuilderFile()throws Exception { /** Get the rule files. */
List drlFilePath = getRuleFile();
/** Sets the file to 'readers'. */
List readers = loadRuleFile(drlFilePath);
/** To create the 'backageBuilder'. */
PackageBuilder backageBuilder = new PackageBuilder();
for (Reader r : readers) {
backageBuilder.addPackageFromDrl(r);
}
/
** Check if the script has a problem. */
if(backageBuilder.hasErrors()) {
throw new Errors().toString());
}
return backageBuilder;
}
氢怎么读
/**
* Load the script files.
* @param drlFilePath
* @return
* @throws FileNotFoundException
*/
private List loadRuleFile(List drlFilePath)
throws FileNotFoundException {
if (null == drlFilePath || 0 == drlFilePath.size()) {
return null;
}
List readers = new ArrayList();
for (String ruleFilePath : drlFilePath) {lfy
readers.add(new FileReader(new File(ruleFilePath)));
}
