Sorry, my mistake. "this" is a reserved word in java (duh!!), and so you need to use your own binding:

m : Message( $message1 : message )
mdup : Message($message2:message==$message1,eval(mdup != m) )

   You can't use mvel dialect, because in MVEL the operators "==" and "!=" will call the equals() method anyway.
   Other than that, it is working just fine for me:

rule "Find duplicates"
        salience 10
    when
        $f1 : Message( $m1 : message )
        $f2 : Message( $m2 : message == $m1, eval( $f1 != $f2 ) )
    then
        System.out.println( "FIRED DUPLICATE:" );
        System.out.println( "      $f1 = "+$f1+" [ message="+$m1+" ]"  );
        System.out.println( "      $f2 = "+$f2+" [ message="+$m2+" ]"  );
end

rule "Find differents"
    when
        $f1 : Message( $m1 : message )
        $f2 : Message( $m2 : message != $m1 )
    then
        System.out.println( "FIRED DIFFERENT:" );
        System.out.println( "      $f1 = "+$f1+" [ message="+$m1+" ]" );
        System.out.println( "      $f2 = "+$f2+" [ message="+$m2+" ]"  );
end

    The code to insert facts is:

            Message message1 = new Message();
            message1.setMessage(  "Hello World" );
            workingMemory.insert( message1 );
            Message message2 = new Message();
            message2.setMessage(  "Hello World" );
            workingMemory.insert( message2 );
            Message message3 = new Message();
            message3.setMessage(  "Hello Bob" );
            workingMemory.insert( message3 );
            workingMemory.fireAllRules();  

    And the result is:

FIRED DUPLICATE:
      $f1 = com.sample.DroolsTest$Message@1b06041 [ message=Hello World ]
      $f2 = com.sample.DroolsTest$Message@1a001ff [ message=Hello World ]
FIRED DUPLICATE:
      $f1 = com.sample.DroolsTest$Message@1a001ff [ message=Hello World ]
      $f2 = com.sample.DroolsTest$Message@1b06041 [ message=Hello World ]
FIRED DIFFERENT:
      $f1 = com.sample.DroolsTest$Message@1c6572b [ message=Hello Bob ]
      $f2 = com.sample.DroolsTest$Message@1b06041 [ message=Hello World ]
FIRED DIFFERENT:
      $f1 = com.sample.DroolsTest$Message@1b06041 [ message=Hello World ]
      $f2 = com.sample.DroolsTest$Message@1c6572b [ message=Hello Bob ]
FIRED DIFFERENT:
      $f1 = com.sample.DroolsTest$Message@1c6572b [ message=Hello Bob ]
      $f2 = com.sample.DroolsTest$Message@1a001ff [ message=Hello World ]
FIRED DIFFERENT:
      $f1 = com.sample.DroolsTest$Message@1a001ff [ message=Hello World ]
      $f2 = com.sample.DroolsTest$Message@1c6572b [ message=Hello Bob ]

    []s
    Edson

2007/11/14, Sikkandar Nawabjan <Sikkandar.Nawabjan@ust-global.com>:
i just use this sort of rule

rule "Hello World"

dialect "mvel"

when

m : Message( $message1 : message )

mdup : Message($message2:message==$message1,eval(this!=m) )

then

System.out.println("Rule Fired1111"+m +"::"+mdup );

System.out.println ("Rule Fired"+$message1 +"::"+$message2 );

end



if i put rule parameter dialect "MVEL"  the error "this should be used in static context" is gone. But now the rule is firing whatever may be the data

i assert 2 objects with message Hello and Hello11111.

still the rule is firing(2 times).

Thanks and regs,

basha




Message: 1
Date: Wed, 14 Nov 2007 09:48:02 -0200
From: "Edson Tirelli" < tirelli@post.com>
Subject: Re: [rules-users] RE: how to find duplicate inlineeval
To: "Rules Users List" <rules-users@lists.jboss.org >
Message-ID:
        <e6dd5ba30711140348p6da77e64kdac90cd313b5aa80@mail.gmail.com>
Content-Type: text/plain; charset="iso-8859-1"

   Sorry, you lost me. What is the error message?
   Can you send us a self contained test showing the problem you are having?

   []s
   Edson

2007/11/14, Sikkandar Nawabjan < Sikkandar.Nawabjan@ust-global.com>:
>
> Edson,
>
> As you said i used inline eval. But am getting erroe message like this
> can't be used in static context.am using statelesssession to assert my
> objects.
>
> i also put eval(this!=obj1) as follows.
>
>   $obj1:Object1($id:id,$name:name)
>   $obj2:Object1(id==$id,$name:name==$name, eval( this!=$obj1
> ))  eval($obj2!=  $obj1)
>
> Though my references are different the rule is not firing
>
>
> Thanks and Regs
>
> Basha
>
> From: rules-users-bounces@lists.jboss.org on behalf of Edson Tirelli
> Sent: Tue 11/13/2007 9:35 PM
> To: Rules Users List
> Subject: Re: [rules-users] RE: how to find duplicate
>
>
>
>
>    Sikkandar,
>
>    The only way to check for identity is to use an inline eval and use
> java code to check that:
>
> when
>         $obj1:Object1($id:id,$name:name)
>         $obj2:Object1(id==$id,$name:name==$name, eval( this!=$obj1 ))
> then
>
>    Another option is to configure your rulebase to not allow the same
> object to be matched by more than one pattern in your rules. To do that you
> can either set a system property:
>
> drools.removeIdentities = true
>
>     Or you can use drools API:
>
> RuleBaseConfiguration conf = new RuleBaseConfiguration();
> conf.setRemoveIdentities( true );
> RuleBase rulebase = RuleBaseFactory.newRuleBase( conf );
>
>     If you do that, your rule can be written as this:
>
> when
>         $obj1:Object1($id:id,$name:name)
>         $obj2:Object1(id==$id,$name:name==$name)
> then
>
>    Since the engine will never allow the same fact to simultaneously match
> both patterns.
>
>    []s
>    Edson



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  Edson Tirelli
  Software Engineer - JBoss Rules Core Developer
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