Drools 7-从DB加载规则
Drools 7-从DB加载规则
提问于 2020-05-18 10:16:29
我用Drools 7作为规则引擎。最初，我使用以下代码从类路径加载规则以构建StatelessKieSession：
KieServices ks = KieServices.Factory.get();
KieContainer kContainer = ks.getKieClasspathContainer();
StatelessKieSession statelessKieSession = kContainer.newStatelessKieSession();然后我决定从DB加载规则，下面是代码：
KnowledgeBuilder knowledgeBuilder = KnowledgeBuilderFactory.newKnowledgeBuilder();
SqlRowSet sqlRowSet = new JdbcTemplate(ds).queryForRowSet("select drl_code from rule");
while(sqlRowSet.next()) {
Resource r = ResourceFactory.newReaderResource(new StringReader(sqlRowSet.getString("drl_code")));
knowledgeBuilder.add(r, ResourceType.DRL);
}
KieBase kieBase = knowledgeBuilder.newKieBase();
StatelessKieSession statelessKieSession = kieBase.newStatelessKieSession();让我担心的是，KnowledgeBuilder接口位于内部包("org.kie.internal")中。
在使用“公共”API从DB加载规则时，是否有另一种方法来构建StatelessKieSession？
回答 1
Stack Overflow用户
发布于 2020-07-05 21:03:08
类似的情况我已经做了如下。我使用MYSQL加载我的规则。
public void reloadRules() {
// TODO Auto-generated method stub
List<DroolsDrlModel> droolsDrlModels = droolsDrlDao.findAll();
KieContainer kieContainer = loadDroolsSessionContainer(droolsDrlModels);
this.kieContainer=kieContainer;
KieSession kieSession = this.kieContainer.newKieSession();
Thread t1 = new Thread(new Runnable() {
public void run() {
kieSession.fireUntilHalt();
}
});
t1.start();
}
public KieContainer loadDroolsSessionContainer(List<DroolsDrlModel> droolsDrlModels){
long startTime = System.currentTimeMillis();
if(this.kieServices == null){
this.kieServices = KieServices.Factory.get();
}
// add following if you are using timer in your rules
KieSessionConfiguration ksconf = kieServices.newKieSessionConfiguration();
ksconf.setOption(TimedRuleExecutionOption.YES);
KieRepository kr = kieServices.getRepository();
KieFileSystem kfs = kieServices.newKieFileSystem();
for(DroolsDrlModel drlModel:droolsDrlModels){
kfs.delete("src/main/resources/" + drlModel.getRuleFileName() + ".drl");
LOGGER.info("Drools DRL was deleted sucessfully"+drlModel.getRuleFileName());
kfs.write("src/main/resources/" + drlModel.getRuleFileName() + ".drl", drlModel.getDroolContent());
LOGGER.info("Drools DRL was created sucessfully "+drlModel.getRuleFileName());
}
KieBuilder kb = kieServices.newKieBuilder(kfs);
kb.buildAll();
if (kb.getResults().hasMessages(Message.Level.ERROR)) {
throw new RuntimeException("Build Errors:\n" + kb.getResults().toString());
}
long endTime = System.currentTimeMillis();
LOGGER.info("Time to build rules : " + (endTime - startTime) + " ms" );
startTime = System.currentTimeMillis();
KieContainer kContainer = kieServices.newKieContainer(kr.getDefaultReleaseId());
endTime = System.currentTimeMillis();
LOGGER.info("Time to load container: " + (endTime - startTime) + " ms" );
return kContainer;
}和我的DroolDrl模型
@Entity(name="rules_table")
public class DroolsDrlModel{
@Column(name = "drl_file_name")
private String ruleFileName;
@Column(name = "drl_content")
private String droolContent;
@Column(name = "version")
private int version;
// getter and setters页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/61867320
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