Drools Use Experience

1.DRL definition:

Package Com.sample

Import com.sample.DroolsTest.Holding;
Import Com.sample.DroolsTest.MatchingRule;

Global Java.util.List batchmatchinglist;

DECLARE customeraddress
Number:int
Streetname:string
City:string
End

function void Printruleinfo () {
int i;
i = 108;
String str = "Define local variable in I rule Engine";
Java.util.List lst = new Java.util.ArrayList ();
Lst.add ("Test1");
Lst.add ("Test2");
SYSTEM.OUT.PRINTLN ("local variable:" + str + ":" + i + ":" + lst.get (1));
}

Rule "Rule 1"
Salience 100
No-loop true
When
Hd:holding ()
Then
System.out.println (Drools.getrule (). GetName () + ":" + hd.getexternalid ());
if (hd.domatching (Matchingrule.matchingbystock)) {
Retract (HD);
}
Drools.setfocus ("G2");
End

Rule "Rule 2"
Salience 99
Agenda-group "G2"
No-loop true
When
Hd:holding ()
Then
System.out.println (Drools.getrule (). GetName () + ":" + hd.getexternalid ());
Hd.domatching (Matchingrule.matchingbyfund);

End

Rule "Rule 3"
Salience 98
Agenda-group "G3"
No-loop true
When
Hd:holding ()
Then
System.out.println (Drools.getrule (). GetName () + ":" + hd.getexternalid ());
Hd.domatching (Matchingrule.matchingbybond);
End

2.java class:

Package com.sample;

Import java.util.ArrayList;

Import org.drools.KnowledgeBase;
Import org.drools.KnowledgeBaseFactory;
Import Org.drools.base.RuleNameEndsWithAgendaFilter;
Import Org.drools.base.RuleNameStartsWithAgendaFilter;
Import Org.drools.builder.KnowledgeBuilder;
Import Org.drools.builder.KnowledgeBuilderError;
Import org.drools.builder.KnowledgeBuilderErrors;
Import org.drools.builder.KnowledgeBuilderFactory;
Import Org.drools.builder.ResourceType;
Import Org.drools.common.DefaultFactHandle;
Import Org.drools.event.rule.DefaultWorkingMemoryEventListener;
Import org.drools.io.ResourceFactory;
Import Org.drools.logger.KnowledgeRuntimeLogger;
Import org.drools.logger.KnowledgeRuntimeLoggerFactory;
Import org.drools.runtime.StatefulKnowledgeSession;
Import org.drools.runtime.rule.Activation;
Import Org.drools.runtime.rule.AgendaFilter;
Import Org.drools.runtime.rule.FactHandle;

/**
* This is a sample class to launch a rule.
*/
public class Droolstest {
private static statefulknowledgesession ksession = null;

private static java.util.map<string, facthandle> holdingmapping = new java.util.hashmap<string, FactHandle > ();

public static final void main (string[] args) {
try {
Load up the Knowledge base
Knowledgebase Kbase = Readknowledgebase ();
Ksession = Kbase.newstatefulknowledgesession ();
Knowledgeruntimelogger logger = Knowledgeruntimeloggerfactory.newfilelogger (ksession, "test");

Java.util.List batchmatchinglist = new ArrayList ();
Ksession.setglobal ("Batchmatchinglist", batchmatchinglist);

Ksession.addeventlistener (New Defaultworkingmemoryeventlistener ());

Go!
Holding HD = new Holding ();
Hd.externalid = "S01";

Holding hd2 = new Holding ();
Hd2.externalid = "D02";

Holding HD3 = new Holding ();
Hd3.externalid = "f03";

Holding hd4 = new Holding ();
Hd4.externalid = "S09";

Facthandle f1 = Ksession.insert (HD);
Facthandle F2 = Ksession.insert (HD2);
Facthandle F3 = Ksession.insert (HD3);
Facthandle F4 = Ksession.insert (HD4);

Holdingmapping.put (Hd.externalid, F1);
Holdingmapping.put (Hd2.externalid, F2);
Holdingmapping.put (Hd3.externalid, F3);
Holdingmapping.put (Hd4.externalid, F4);

Ksession.fireallrules (New Rulenamestartswithagendafilter ("F"));
Ksession.fireallrules ();

Logger.close ();
catch (Throwable t) {
T.printstacktrace ();
}
}

 private Static Knowledgebase Readknowledgebase () throws Exception {
  knowledgebuilder kbuilder = Knowledgebuilderfactory.newknowledgebuilder ();
  kbuilder.add (Resourcefactory.newclasspathresource ("MATCHBYID.DRL"), RESOURCETYPE.DRL);
  //kbuilder.add (Resourcefactory.newclasspathresource ("MATCHBYDETAIL.DRL"), ResourceType.DRL);
  knowledgebuildererrors errors = kbuilder.geterrors ();
  if (errors.size () > 0) {
   for (knowledgebuildererror error:errors) {
  &NBSP;&NBSP;&NBSP;SYSTEM.ERR.PRINTLN (Error);
   }
   throw New IllegalArgumentException ("could not parse knowledge.");
  }
  knowledgebase kbase = Knowledgebasefactory.newknowledgebase ();
  kbase.addknowledgepackages (Kbuilder.getknowledgepackages ());
  return kbase;
 }

public static class Holding {
Private String Externalid;
Private String Externalname;

Public String Getexternalid () {
return externalid;
}

Public String Getexternalname () {
return externalname;
}

public void dobatchmatching (Matchingrule matchingrule) {
Java.util.List batchmatchinglist = (java.util.List) ksession.getglobal ("Batchmatchinglist");

for (int i = 0; i < batchmatchinglist.size (); i++) {
String externalid = (string) batchmatchinglist.get (i);

    boolean ismatched = false;
    switch (matchingrule) {
    case matchingbystock:
      if (Externalid.startswith ("S0")) {
      ismatched = True ;
     }
     break;
    case Matchingbybond:
     if (Externalid = = "D02") {
      ismatched = true;
     }
     break;
    case matchingbyfund:
     if (Externalid = = "F03") {
      ismatched = true;
     }
     break;

Default
Break
}
if (ismatched) {
System.out.println ("==> backend matched:" + matchingrule + "--->>>" + externalid);

Facthandle handle = Holdingmapping.get (Externalid);
DroolsTest.ksession.retract (handle);
}
}

Ksession.getagenda (). Getagendagroup ("afterdomatching"). SetFocus ();

Ksession.fireallrules (New Rulenamestartswithagendafilter ("afterdomatching"));
}

  public Boolean domatching (matchingrule matchingrule) {
   boolean = false;
   switch (matchingrule) {
   case matchingbystock:
     if (Externalid.startswith ("S0")) {
     ismatched = true;
    &NBSP}
    break
   case matchingbybond:
     if (Externalid = = "D02") {
     ismatched = true;
    }
     break;
   case matchingbyfund:
    if (Externalid = = "F03") {
      ismatched = true;
    }
    break;

Default
Break
}
if (ismatched) {
System.out.println ("==> backend matched:" + matchingrule + "--->>>" + externalid);

Facthandle handle = DroolsTest.ksession.getFactHandle (this);
DroolsTest.ksession.retract (handle);
}
return ismatched;
}

}

public static enum Matchingrule {
Matchingbystock, Matchingbybond, Matchingbyfund,
}

}

Multiple fact, such as: M a c1,n a c2, the most to deal with m*n rule, preferably in the process of fact, retract off the current fact