building a lookup step in a UDJC

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Jan 16, 2015, 7:58:38 AM1/16/15

I've built a lookupstep in a UDJC and it works fine in a simple test case.

However in the real world what seems to happen is that the transformation hangs.

I suspect this is because although my step has finished processing the input stream, it hasn't consumed all the lookup stream data.  Therefore the step feeding the lookup stream doesn't end.

So, short of simply calling getrows loads of times until they are all consumed, is there any other way to say "Oi, I'm done, just die"?


Matt Casters

Jan 16, 2015, 9:00:53 AM1/16/15
to Kettle Developers mailing list
Fortunately there is no "ignore all these" rows method.
So the only option left to forcefully stop the transformation is to actually call stopAll();

I find the use-case a bit dubious though.  How would you know that you read all the lookup data and where to stop?  That's just one question I would have in this situation.

I think that instead you just need to make sure you depleted all the steps from a specific (what we call) info-step before starting to read from all other steps. From

    RowSet rowSet = findInputRowSet( data.infoStream.getStepname() );
    Object[] rowData = getRowFrom( rowSet ); // rows are originating from "lookup_from"
    while ( rowData != null ) {
        ... do something....
        rowData = getRowFrom( rowSet );

and only then call getRow() as before.

Good luck!

Matt Casters <>
Chief Data Integration, Kettle founder, Author of Pentaho Kettle Solutions (Wiley)
Fonteinstraat 70 - 9400 OKEGEM - Belgium - Cell : +32 486 97 29 37
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Jan 16, 2015, 9:04:52 AM1/16/15
Perfect, thanks. I plan a blog to explain my specific use case in the next few weeks with source too :-)
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