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<DIV dir=ltr align=left><SPAN class=046173009-29012007><FONT face=Arial
color=#0000ff size=2>You'll probably need to ensure the String object contains a
valid object reference and not a null.</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=046173009-29012007><FONT face=Arial
color=#0000ff size=2></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=046173009-29012007><FONT face=Arial
color=#0000ff size=2>If the database allows NULL values on a field then the
String object will be set to a null causing the problem you explain. An
alternative is to either set the String to an empty String ("") instead of null
or change your rule to first check whether the String is a null; for example
<FONT face="Courier New">beanObject.getName() != null &&
beanObject.getName()=="smurf"</FONT>.</FONT></SPAN></DIV><BR>
<BLOCKQUOTE style="MARGIN-RIGHT: 0px">
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<HR tabIndex=-1>
<FONT face=Tahoma size=2><B>From:</B> rules-users-bounces@lists.jboss.org
[mailto:rules-users-bounces@lists.jboss.org] <B>On Behalf Of
</B>Mahantesh<BR><B>Sent:</B> 29 January 2007 08:58<BR><B>To:</B>
rules-users@lists.jboss.org<BR><B>Subject:</B> [rules-users] required some
input on String comparision in xml rulefile.<BR></FONT><BR></DIV>
<DIV></DIV><SPAN class=gmail_quote></SPAN>Hi,<BR><BR>I am using Drools 3 JBoss
Rule Engine and xml file as a rule file. when i am using integer condition in
LHS part of rule file it is working fine. <BR>For example: <eval>
beanObject.getNumber >= 60 </eval> <BR><BR>but when using
string condition in LHS part of the rule file, it is able to filter the data
when setting and getting the data from the dummy bean, but not able to filter
the data when the data is coming from the database its throwing the exceptions
like this. <BR><BR>For Example: <eval>
beanObject.getName()</eval><BR><BR>Exception like
this.<BR><BR>org.drools.RuntimeDroolsExcept
<DIV style="DIRECTION: ltr">ion: java.lang.NullPointerException<BR>
at org.drools.rule.EvalCondition.isAllowed (Unknown
Source)<BR> at
org.drools.reteoo.EvalConditionNode.assertTuple(Unknown Source)<BR>
at
org.drools.reteoo.TupleSource.propagateAssertTuple(Unknown Source)<BR>
at org.drools.reteoo.JoinNode.assertObject (Unknown
Source)<BR> at
org.drools.reteoo.ObjectSource.propagateAssertObject(Unknown Source)<BR>
at org.drools.reteoo.ObjectTypeNode.assertObject(Unknown
Source)<BR> at org.drools.reteoo.Rete.assertObject
(Unknown Source)<BR> at
org.drools.reteoo.ReteooRuleBase.assertObject(Unknown Source)<BR>
at org.drools.reteoo.ReteooWorkingMemory.doAssertObject(Unknown
Source)<BR> at
org.drools.common.AbstractWorkingMemory.assertObject (Unknown
Source)<BR> at
org.drools.common.AbstractWorkingMemory.assertObject(Unknown Source)<BR>
at
org.drools.jsr94.rules.StatelessRuleSessionImpl.executeRules(Unknown
Source)<BR> at
org.drools.jsr94.rules.StatelessRuleSessionImpl.executeRules (Unknown
Source)<BR> at
rules1.TestRuleForXML.applyRuleTestingProcessVO(TestRuleForXML.java:176)<BR>
at
rules1.TestRuleForXML.applyForProcessVO(TestRuleForXML.java:55)<BR>size of the
ouput list in java file: 0 <BR><BR> at
rules1.TestRuleForXML.main(TestRuleForXML.java:47)<BR>Caused by:
java.lang.NullPointerException<BR> at
rules1.Rule_my_rule_0.eval0(Rule_my_rule_0.java:12)<BR>
at rules1.Rule_my_rule_0Eval0Invoker.evaluate
(Rule_my_rule_0Eval0Invoker.java:19)<BR><BR>If you do a help regarding how to
work with String condition in LHS part, it will be great..<BR><BR>Thanks in
Advance,<BR>Mahantesh.<BR></DIV><BR><BR><BR><BR><BR></BLOCKQUOTE></BODY></HTML>