10:24 p.m.
Hi,
I am getting null pointer exception when i retract objects from working
memory. please help me in resolving this problem....
my rule goes like this...
package com.moto.nms
import com.moto.nms.Event;
import com.adventnet.nms.topodb.ManagedObject;
import com.motorola.nmatg.nms.topology.ManagedEntity;
global com.moto.nms.Consecutive con; // Consecutive is an simple
class file which has two simple methods, getValue() and setValue().
rule "duplicate"
salience 29
when
e1 : Event( firsttime1 : time , severity1 : severity == 1 )
e2 : Event( firsttime2 : time > firsttime1 , severity == severity1 )
not Event( severity == -1 , time > firsttime1 , time < firsttime2)
then
System.out.println("matched the fact");
e1.setCompressionStatus("compress_"+con.getValue());
e2.setCompressionStatus("compress_"+con.getValue());
end
rule "duplicate_x"
salience 29
when
e1 : Event(firsttime1 : time , severity == 1 )
e2 : Event(firsttime2 : time > firsttime1 , severity == 1)
exists Event( severity == -1, time > firsttime1 , time < firsttime2)
then
System.out.println("matched 2nd fact");
con.setValue(con.getValue() +1);
end
exception is like this...
Caught Exceptionjava.lang.NullPointerException
java.lang.NullPointerException
at org.drools.reteoo.beta.DefaultRightMemory.remove(Unknown Source)
at org.drools.reteoo.BetaMemory.remove(Unknown Source)
at org.drools.reteoo.NotNode.retractObject(Unknown Source)
at org.drools.reteoo.ObjectSource.propagateRetractObject(Unknown Source)
at org.drools.reteoo.RightInputAdapterNode.retractTuple(Unknown Source)
at org.drools.reteoo.TupleSource.propagateRetractTuple(Unknown Source)
at org.drools.reteoo.NotNode.retractTuple(Unknown Source)
at org.drools.reteoo.TupleSource.propagateRetractTuple(Unknown Source)
at org.drools.reteoo.JoinNode.retractTuple(Unknown Source)
at org.drools.reteoo.LeftInputAdapterNode.retractObject(Unknown Source)
at org.drools.reteoo.ObjectSource.propagateRetractObject(Unknown Source)
at org.drools.reteoo.AlphaNode.retractObject(Unknown Source)
at org.drools.reteoo.ObjectSource.propagateRetractObject(Unknown Source)
at org.drools.reteoo.ObjectTypeNode.retractObject(Unknown Source)
at org.drools.reteoo.Rete.retractObject(Unknown Source)
at org.drools.reteoo.ReteooRuleBase.retractObject(Unknown Source)
at org.drools.reteoo.ReteooWorkingMemory.doRetract(Unknown Source)
at org.drools.common.AbstractWorkingMemory.retractObject(Unknown Source)
at org.drools.common.AbstractWorkingMemory.retractObject(Unknown Source)
at com.moto.nms.TestEvents3.retractAll(TestEvents3.java:219)
at com.moto.nms.TestEvents3.readRule(TestEvents3.java:158)
at com.moto.nms.TestEvents3.main(TestEvents3.java:242)
TestEvents3.java class is like this....
package com.moto.nms;
//related to IO..
import java.io.InputStreamReader;
import java.io.Reader;
import java.io.InputStream;
import java.util.List;
import java.util.Iterator;
//related to Drools..
import org.drools.RuleBase;
import org.drools.RuleBaseFactory;
import org.drools.compiler.PackageBuilder;
import org.drools.rule.Package;
import org.drools.WorkingMemory;
import org.drools.FactHandle;
import org.drools.FactException;
import com.moto.nms.Event;
import com.moto.nms.NMSEvent;
import com.moto.nms.TopoInterface1;
import com.moto.nms.GenerateEvents;
import com.adventnet.nms.topodb.ManagedObject;
import com.moto.nms.Consecutive;
public class TestEvents3 {
private Reader reader;
private RuleBase rulebase;
private WorkingMemory wm;
private List factHandles;
public TestEvents3(){
}
public void readRule(String readername) throws Exception{
InputStream str = null;
str = TestEvents.class.getResourceAsStream(readername);
if(str == null)
{
System.out.println("unable to read rule file");
return;
}
reader = new InputStreamReader(str); //read in the source
PackageBuilder builder = new PackageBuilder(); //building up the rule
package
builder.addPackageFromDrl(reader);
Package pkg = builder.getPackage(); //get the compiled package
rulebase = RuleBaseFactory.newRuleBase();
rulebase.addPackage( pkg ); //adding the package to the rule base
Consecutive con = new Consecutive();
wm = rulebase.newWorkingMemory();
wm.setGlobal("con", con);
System.out.println("\n\n"+System.currentTimeMillis());
Event ev1 = new Event(183, 1, "port02", "LOS",
System.currentTimeMillis());
//Thread.sleep(450);
Event ev9 = new Event(192, 1, "port02", "LOS",
System.currentTimeMillis());
//Thread.sleep(400);
Event ev10 = new Event(307, 1, "port02", "LOS",
System.currentTimeMillis());
Thread.sleep(500);
Event ev11= new Event(306, 1, "port02", "LOS",
System.currentTimeMillis());
Thread.sleep(200);
Event ev12= new Event(305, 1, "port02", "LOS",
System.currentTimeMillis());
Thread.sleep(250);
Event ev13= new Event(304, -1, "port02", "LOS",
System.currentTimeMillis());
Thread.sleep(600);
Event ev14= new Event(302, 1, "port02", "LOS",
System.currentTimeMillis());
Thread.sleep(200);
Event ev15= new Event(301, 1, "port02", "LOS",
System.currentTimeMillis());
Thread.sleep(200);
Event ev16= new Event(308, 1, "port02", "LOS",
System.currentTimeMillis());
wm.assertObject(ev1);
wm.assertObject(ev9);
wm.assertObject(ev10);
wm.assertObject(ev11);
wm.assertObject(ev12);
wm.assertObject(ev13);
wm.assertObject(ev14);
wm.assertObject(ev15);
wm.assertObject(ev16);
System.out.println("\n\n"+System.currentTimeMillis());
System.out.println("\n\nFiring rules...\n");
wm.fireAllRules();
factHandles = wm.getObjects();
System.out.println("\n\nAll the Objects in WOrking Memory are as
Follows...\n");
for(int i=0; i<factHandles.size(); i++)
{
System.out.println(factHandles.get(i));
}
System.out.println("The CompressionStatus of the events are...");
System.out.println(ev1.getCompressionStatus());
System.out.println(ev9.getCompressionStatus());
System.out.println(ev10.getCompressionStatus());
System.out.println(ev11.getCompressionStatus());
System.out.println(ev12.getCompressionStatus());
System.out.println(ev13.getCompressionStatus());
System.out.println(ev14.getCompressionStatus());
System.out.println(ev15.getCompressionStatus());
System.out.println(ev16.getCompressionStatus());
System.out.println("The DeletionStatus of the events are...");
System.out.println(ev1.getDeletionStatus());
System.out.println(ev9.getDeletionStatus());
System.out.println(ev10.getDeletionStatus());
System.out.println(ev11.getDeletionStatus());
System.out.println(ev12.getDeletionStatus());
System.out.println(ev13.getDeletionStatus());
System.out.println(ev14.getDeletionStatus());
System.out.println(ev15.getDeletionStatus());
System.out.println(ev16.getDeletionStatus());
Thread.sleep(1000);
System.out.println("Starting retracting....");
Thread.sleep(1000);
retractAll();
System.out.println(System.currentTimeMillis());
}
public void retractAll()
{
factHandles = wm.getFactHandles();
Iterator itr = factHandles.iterator();
if(factHandles == null)
{
System.out.println("invalid FactHandler List");
return;
}
System.out.println("size of fact handles..:"+factHandles.size());
while(itr.hasNext())
{
try{
FactHandle fh = (FactHandle)itr.next();
if(fh == null)
System.out.println("Here object is null, Cannot be retracted");
else
{
wm.retractObject(fh);
System.out.println("Retracted object : "+ fh);
}
}catch (FactException e){
e.printStackTrace();
}
}
return;
}
public static void main(String[] args){
TestEvents3 te = new TestEvents3();
try{
te.readRule("/AlarmSuppression.drl");
}catch(Exception ex){
System.out.println("Caught Exception" +ex);
ex.printStackTrace();}
}
}