规则引擎Drools在贷后催收业务中的应用

if(overdueDays>a && overdueDays<b && overdueAmt <W){
    taskQuene = "A队列";
}
else if(overdueDays>c && overdueDays<d && overdueAmt <W){
    taskQuene = "B队列";
}
else if(overdueDays>e && overdueDays<f && overdueAmt <W){
    taskQuene = "C队列";
}
else if(overdueDays>h && overdueDays<g && overdueAmt <W){
    taskQuene = "D队列";
}
……

package  //包名，这个包名只是逻辑上的包名，不必与物理包路径一致。
 
import   //导入类 同java
 
function  //  自定义函数
 
query  //  查询
 
global   //  全局变量
 
rule "rule name"  //  定义规则名称，名称唯一不能重复
    attribute //  规则属性
    when
        //  规则条件
    then
        //  触发行为
end
 
rule "rule2 name"
 
...

function String hello(String applicantName) {
    return "Hello " + applicantName + "!";
}
 
rule "Using a function"
  when
    // Empty
  then
    System.out.println( hello( "James" ) );
end

query "people under the age of 21"
    $person : Person( age < 21 )
end

QueryResults results = ksession.getQueryResults( "people under the age of 21" );
System.out.println( "we have " + results.size() + " people under the age  of 21" );

List<String> list = new ArrayList<>();
KieSession kieSession = kiebase.newKieSession();
kieSession.setGlobal( "myGlobalList", list );

global java.util.List myGlobalList;
 
rule "Using a global"
  when
    // Empty
  then
    myGlobalList.add( "My global list" );
end

rule "Underage"
  when
    application : LoanApplication()//表示存在Application事实对象且age属性满足<21
    Applicant( age < 21 )
  then
    // Actions
end

rule "Underage"
  when
    application : LoanApplication()
    Applicant( age < 21 )
  then
    application.setApproved( false );
end

rule "Underage"
  when
    Applicant( age < 21 )
  then
    Applicant application = new application();
    application.setAge(22);
    insert(application);//插入fact重新匹配规则，age>21的规则直接被触发
end

rule "Underage"
  when
    Applicant( age < 21 )
  then
    Applicant application = new application();
    application.setAge(22);
    insert(application);//插入fact重新匹配规则，age>21的规则直接被触发
end

<kmodule xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xmlns="http://www.drools.org/xsd/kmodule">
  <kbase name="KBase1" default="true" packages="org.domain.pkg1">
    <ksession name="KSession2_1" type="stateful" default="true"/>
    <ksession name="KSession2_2" type="stateless" default="false"/>
  </kbase>
  <kbase name="KBase2" default="false" packages="org.domain.pkg2, org.domain.pkg3">
    <ksession name="KSession3_1" type="stateful" default="false">
    </ksession>
  </kbase>
</kmodule>

KieServices kieServices = KieServices.Factory.get();
KieContainer kContainer = kieServices.getKieClasspathContainer();
KieBase kBase1 = kContainer.getKieBase("KBase1"); //获取指定的KBase
KieSession kieSession1 = kContainer.newKieSession("KSession2_1"); //获取指定的KSession
kieSession1.insert(facts);//规则插入到工作内存
kSession.fireAllRules();//开始执行
kSession.dispose();//关闭对话

rule "Rete"
  when
    A(a1==1,$a:a1)
    B(b1==1,b1==$a,$b:b2)
    C(c2==$b)
  then
    System.out.print("匹配成功");
end

rule "Rete1"
when
    Cheese( $cheddar : name == "cheddar" )
    $person : Person( favouriteCheese == $cheddar )
then
    System.out.println( $person.getName() + " likes cheddar" );
end
 
rule "Rete2"
when
    Cheese( $cheddar : name == "cheddar" )
    $person : Person( favouriteCheese != $cheddar )
then
    System.out.println( $person.getName() + " does not like cheddar" );
end

package vivoPhoneTaskRule;
 
import com.worldline.wcs.service.rule.CaseSumNewWrapper;
 
 
rule "rule1"
    salience 1
    when
        caseSumNew:CaseSumNewWrapper(overdueDD > a && overdueDD < b && overdueAmt <= W)
    then
        caseSumNew.setTaskType("A队列");
end
 
rule "rule2"
    salience 2
    when
        caseSumNew:CaseSumNewWrapper(overdueDD > c && overdueDD < d && overdueAmt <= W)
    then
        caseSumNew.setTaskType("B队列");
end
 
rule "rule3"
    salience 3
    when
        caseSumNew:CaseSumNewWrapper(overdueDD > e && overdueDD < f && overdueAmt <= W)
    then
        caseSumNew.setTaskType("C队列");
end
 
rule "rule4"
    salience 4
    when
        caseSumNew:CaseSumNewWrapper(overdueDD > h && overdueDD < g && overdueAmt > W)
    then
        caseSumNew.setTaskType("D队列");
end

<rule package="phoneTask">
    <entitys>
        <entity note="collectionCaseInfo" cls="com.worldline.wcs.service.rule.FactWrapper" alias="caseSumNew">
            <attribute attr="caseSumNew.overdueDD" />
            <attribute attr="caseSumNew.totalOverdueAmt"/>
        </entity>
    </entitys>
    <resultDefs>
        <resultDef key="1" seq="1" enumKey="ruleTaskType">
            <script><![CDATA[caseSumNew.setTaskType("@param");]]></script>
        </resultDef>
    </resultDefs>
</rule>

/**
* 生成规则脚本
* rule规则基本信息：包括规则表字段名定义等
* def 业务人员具体录入规则集的条件和结果等数据
*/
public String generateDRLScript(DroolsRuleEditBO rule, DroolsRuleTableBO def) {
        //解析事实对象映射XML文件，生成条件定义与结果定义
        RuleSetDef ruleSetDef = RuleSetDefHelper.getRuleSetDef(rule.getRuleTypeCode());
 
        // 1.声明规则包
        StringBuilder drl = new StringBuilder("package ").append(rule.getRuleTypeCode()).append(";\n\n");
        HashMap<String, String> myEntityMap = Maps.newHashMap(); // k,v => caseSumNew,CaseSumNewWrapper
        // 2.导入 entity 对应执行类
        ruleSetDef.getEntitys().forEach(d -> {
            String cls = d.getCls();
            drl.append("import ").append(cls).append(";\n\n");
            myEntityMap.put(d.getAlias(), cls.substring(cls.lastIndexOf('.') + 1));
        });
        // 3.规则脚本注释
        drl.append("// ").append(rule.getRuleTypeCode()).append(" : ").append(rule.getRuleTypeName()).append("\n");
        drl.append("// version : ").append(rule.getCode()).append("\n");
        drl.append("// createTime : ").append(DateUtil.getSysDate(DateUtil.PATTERN_TIME_DEFAULT)).append("\n\n");
 
        Map<String, String> myResultMap = def.getResultDefs().stream().collect(Collectors.toMap(DroolsRuleCondBO::getCondKey, DroolsRuleCondBO::getScript));
 
        // 4.写规则
        AtomicInteger maxRowSize = new AtomicInteger(0); // 总规则数
        rule.getTables().forEach(table -> {
            String tableCode = table.getTableCode();
            table.getRows().stream().filter(r -> !Objects.equals(r.getStatus(), 3))
           .forEach(row -> {
                // 3.1.规则属性及优先级
                drl.append("// generated from row: ").append(row.getRowCode()).append("\n");
                //TODO 需要保证row.getRowSort()不重复，否则生成同样的规则编号
                drl.append("rule \"").append(rule.getRuleTypeCode()).append("_").append(tableCode).append("_TR_").append(row.getRowSort()).append("\"\n");  // pkg_tableCode_TR_rowSort
                drl.append("\tsalience ").append((maxRowSize.incrementAndGet())).append("\n");
 
                // 4.2.条件判定
                drl.append("\twhen\n");
                // 每个entity一行,多条件合并
                // when=condEntityKey:cls(condKeyMethod colOperator.drlStr colValue), 其中cls=myEntityMap.value(key=condEntityKey)
                drl.append(
                        row.getColumns()
                                .stream().collect(Collectors.groupingBy(d -> d.getCondition().getCondEntityKey()))
                                .entrySet().stream()
                                .map(entityType -> "\t\t" + entityType.getKey() + ":" + myEntityMap.get(entityType.getKey()) + "(" +
                                        entityType.getValue().stream()
                                                .filter(col -> StringUtils.isNotBlank(col.getColValue())) // 排除无效条件
                                                .sorted(Comparator.comparing(col -> col.getCondition().getCondSort())) // 排序
                                                .map(col -> {
                                                    String condKey = col.getCondition().getCondKey();
                                                    String condKeyMethod = condKey.substring(condKey.indexOf('.') + 1);
                                                    String[] exec = ParamTypeHelper.get(col.getColOperator()).getDrlStr(condKeyMethod, col.getColValue());
                                                    if (exec.length > 0) {
                                                        return Arrays.stream(exec).filter(StringUtils::isNotBlank).collect(Collectors.joining(" && "));
                                                    }
                                                    return null;
                                                })
                                                .collect(Collectors.joining(" && ")) + ")\n"
                                )
                                .collect(Collectors.joining()));
 
                // 4.3.规则结果
                drl.append("\tthen\n");
                row.getResults().forEach(r -> {
                    String script = myResultMap.get(r.getResultKey());
                    drl.append("\t\t").append(script.replace("@param", r.getResultValue())).append("\n"); // 使用 resultValue 替换 @param
                });
                drl.append("end\n\n");
            });
        });
        return drl.toString();
    }

//核心流程代码：
KnowledgeBuilder kb = KnowledgeBuilderFactory.newKnowledgeBuilder();
kb.add(ResourceFactory.newByteArrayResource(script.getBytes(StandardCharsets.UTF_8)), ResourceType.DRL); //script为规则脚本
InternalKnowledgeBase base = KnowledgeBaseFactory.newKnowledgeBase();
KieSession ksession = base.newKieSession();
AgendaFilter filter = RuleConstant.DroolsRuleNameFilter.getFilter(ruleTypeCode);//获取一个过滤器
kSession.insert(fact);
kSession.fireAllRules(filter);
kSession.dispose();