Lookup data in any data reader

/*
* Copyright (c) 2006-2010 North Concepts Inc.  All rights reserved.
* Proprietary and Confidential.  Use is subject to license terms.
*
* http://northconcepts.com/data-pipeline/licensing/
*
*/
package com.northconcepts.datapipeline.examples.cookbook;

import java.io.File;

import com.northconcepts.datapipeline.core.DataReader;
import com.northconcepts.datapipeline.core.FieldList;
import com.northconcepts.datapipeline.core.StreamWriter;
import com.northconcepts.datapipeline.csv.CSVReader;
import com.northconcepts.datapipeline.job.JobTemplate;
import com.northconcepts.datapipeline.transform.TransformingReader;
import com.northconcepts.datapipeline.transform.lookup.DataReaderLookup;
import com.northconcepts.datapipeline.transform.lookup.Lookup;
import com.northconcepts.datapipeline.transform.lookup.LookupTransformer;

public class LookupDataInAnyDataReader {
   
    public static void main(String[] args) throws Throwable {
        DataReader reader = new CSVReader(new File("example/data/input/credit-balance-01.csv"))
            .setFieldNamesInFirstRow(true);
       
        TransformingReader transformingReader = new TransformingReader(reader);

        /* This lookup matches
         *    [credit-balance-01.csv].[Rating] to [rating-table-01.csv].[rating_code]
         * to return   
         *   [rating-table-01.csv].[rating_description]
         */
        Lookup lookup = new DataReaderLookup(
                new CSVReader(new File("example/data/input/rating-table-01.csv"))
                    .setFieldNamesInFirstRow(true),
                new FieldList("rating_code"),
                new FieldList("rating_description")
                );
       
        transformingReader.add(new LookupTransformer(
                new FieldList("Rating"), 
                lookup
                ));
       
        JobTemplate.DEFAULT.transfer(transformingReader, new StreamWriter(System.out));
    }
   
}

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