Hi.

I don't understand quite well this approach. Could you provide an example please.

But it could be more useful, to inject in dbhelper an object that give me the access to
JNID tree of servicemix.

Is there a way to do this, now in my customized version od DroolsHelper i get the context and
i pass to dbhelper as follow.

protected void populateWorkingMemory(WorkingMemory memory, MessageExchange exchange) throws Exception {
       memory.setGlobal("jbi", new JbiHelper(this, exchange, memory));
EndpointComponentContext aContext = (EndpointComponentContext)getContext();
       InitialContext jndiContext = aContext.getNamingContext();
       memory.assertObject(new DbHelper(jndiContext));
   }

What i need is only a way to inject such object in spring xbean file.

Is this possible??




rgavlin ha scritto:
Hi,

How about using xbean/spring as in the referenced blog to populate the
Drools globals map with key/value pairs, the key being the datasource name
and the value begin a DbHelper instance that wraps the corresponding
datasource instance? In the drools file, one can reference the desired
DbHelper by datasource name key. Using this technique, there should be no
need to package the DbHelper class within the Drools SE component.

- Ron


Andrea Zoppello-2 wrote:
Hi all,

I need to use drools servicemix component, and in my rules, i need to use a db helper object to
evaluate some rule conditions against database.

I've just read the very good approach, proposed in http://gnodet.blogspot.com/2007/06/accessing-databases-in-servicemix.html.

The only problem, that i've with this approach is that some of my customer, want to have in the dbhelper methods, a parameter that switch the datasource to use for a query:

for example they want to write something like:


package org.apache.servicemix.drools
import org.apache.servicemix.drools.model.Exchange;
import org.apache.servicemix.drools.model.DbHelper;
global org.apache.servicemix.drools.model.JbiHelper jbi;

    rule "Rule1"
    when
        me : Exchange( status == Exchange.ACTIVE, in : in != null );
        db : DbHelper ( );
eval( db.exist( in.valueOf("/ACTION/@name"), "STRING", "attribute", "name", "ds1" ) );
    then
        jbi.fault( "<ERROR> The value is already present in db </ERROR>"
);
    end

    rule "Rule1"
    when
        me : Exchange( status == Exchange.ACTIVE, in : in != null );
        db : DbHelper ( );
eval( db.exist( in.valueOf("/ACTION/@name"), "STRING", "attribute", "name", "ds2" ) );
    then
        jbi.fault( "<ERROR> The value is already present in db </ERROR>"
);
    end

where the last parameter of db.exist method identidies the datasource and they could have rules that
switch from ds1 to ds2.

To do this it could be enough to have an object that let's my helper to access the jndi context of servicemix.

To get this type of behaviour at the moment, we've a customized version of servicemix-drools, but
in future i'd like to rely on the standard component.

Is this possible to achieve this, maybe injectiong in a helper object that lets me to access to jndi of servicemix???


Thanks in advance


Andrea






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