SwitchCase.java

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 * Pentaho Data Integration
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 * Copyright (C) 2002-2016 by Pentaho : http://www.pentaho.com
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 * Licensed under the Apache License, Version 2.0 (the "License");
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package org.pentaho.di.trans.steps.switchcase;

import java.util.List;
import java.util.Set;

import org.pentaho.di.core.RowSet;
import org.pentaho.di.core.exception.KettleException;
import org.pentaho.di.core.row.ValueMetaInterface;
import org.pentaho.di.core.row.value.ValueMetaFactory;
import org.pentaho.di.core.util.Utils;
import org.pentaho.di.i18n.BaseMessages;
import org.pentaho.di.trans.Trans;
import org.pentaho.di.trans.TransMeta;
import org.pentaho.di.trans.step.BaseStep;
import org.pentaho.di.trans.step.StepDataInterface;
import org.pentaho.di.trans.step.StepIOMetaInterface;
import org.pentaho.di.trans.step.StepInterface;
import org.pentaho.di.trans.step.StepMeta;
import org.pentaho.di.trans.step.StepMetaInterface;
import org.pentaho.di.trans.step.errorhandling.StreamInterface;

/**
 * Filters input rows base on conditions.
 *
 * @author Matt
 * @since 16-apr-2003, 07-nov-2004 (rewrite)
 */
public class SwitchCase extends BaseStep implements StepInterface {
  private static Class<?> PKG = SwitchCaseMeta.class; // for i18n purposes, needed by Translator2!!

  private SwitchCaseMeta meta;
  private SwitchCaseData data;

  public SwitchCase( StepMeta stepMeta, StepDataInterface stepDataInterface, int copyNr, TransMeta transMeta,
                     Trans trans ) {
    super( stepMeta, stepDataInterface, copyNr, transMeta, trans );
  }

  public boolean processRow( StepMetaInterface smi, StepDataInterface sdi ) throws KettleException {
    meta = (SwitchCaseMeta) smi;
    data = (SwitchCaseData) sdi;

    Object[] r = getRow(); // Get next usable row from input rowset(s)!
    if ( r == null ) { // no more input to be expected...

      setOutputDone();
      return false;
    }

    if ( first ) {
      first = false;

      // map input to output streams
      createOutputValueMapping();
    }

    // We already know the target values, but we need to make sure that the input data type is the same as the specified
    // one.
    // Perhaps there is some conversion needed.
    //
    Object lookupData = data.valueMeta.convertData( data.inputValueMeta, r[data.fieldIndex] );

    // Determine the output set of rowset to use...
    Set<RowSet> rowSetSet = ( data.valueMeta.isNull( lookupData ) ) ? data.nullRowSetSet : data.outputMap.get( lookupData );

    // If the rowset is still not found (unspecified key value, we drop down to the default option
    // For now: send it to the default step...
    if ( rowSetSet == null ) {
      rowSetSet = data.defaultRowSetSet;
    }

    for ( RowSet rowSet : rowSetSet ) {
      putRowTo( data.outputRowMeta, r, rowSet );
    }

    if ( checkFeedback( getLinesRead() ) ) {
      if ( log.isBasic() ) {
        logBasic( BaseMessages.getString( PKG, "SwitchCase.Log.LineNumber" ) + getLinesRead() );
      }
    }

    return true;
  }

  /**
   * @see StepInterface#init(org.pentaho.di.trans.step.StepMetaInterface , org.pentaho.di.trans.step.StepDataInterface)
   */
  public boolean init( StepMetaInterface smi, StepDataInterface sdi ) {
    meta = (SwitchCaseMeta) smi;
    data = (SwitchCaseData) sdi;

    if ( !super.init( smi, sdi ) ) {
      return false;
    }
    data.outputMap = meta.isContains() ? new ContainsKeyToRowSetMap() : new KeyToRowSetMap();

    if ( Utils.isEmpty( meta.getFieldname() ) ) {
      logError( BaseMessages.getString( PKG, "SwitchCase.Log.NoFieldSpecifiedToSwitchWith" ) );
      return false;
    }

    try {
      data.valueMeta = ValueMetaFactory.createValueMeta( meta.getFieldname(), meta.getCaseValueType() );
      data.valueMeta.setConversionMask( meta.getCaseValueFormat() );
      data.valueMeta.setGroupingSymbol( meta.getCaseValueGroup() );
      data.valueMeta.setDecimalSymbol( meta.getCaseValueDecimal() );
      data.stringValueMeta = ValueMetaFactory.cloneValueMeta( data.valueMeta, ValueMetaInterface.TYPE_STRING );
    } catch ( Exception e ) {
      logError( BaseMessages.getString( PKG, "SwitchCase.Log.UnexpectedError", e ) );
    }

    return true;
  }

  /**
   * This will prepare step for execution:
   * <ol>
   * <li>will copy input row meta info, fields info, etc. step related info
   * <li>will get step IO meta info and discover target streams for target output steps
   * <li>for every target output find output rowset and expected value.
   * <li>for every discovered output rowset put it as a key-value: 'expected value'-'output rowSet'. If expected value
   * is null - put output rowset to special 'null set' (avoid usage of null as a map keys)
   * <li>Discover default row set. We expect only one default rowset, even if technically can have many. *
   * </ol>
   *
   * @throws KettleException
   *           if something goes wrong during step preparation.
   */
  void createOutputValueMapping() throws KettleException {
    data.outputRowMeta = getInputRowMeta().clone();
    meta.getFields( getInputRowMeta(), getStepname(), null, null, this, repository, metaStore );

    data.fieldIndex = getInputRowMeta().indexOfValue( meta.getFieldname() );
    if ( data.fieldIndex < 0 ) {
      throw new KettleException( BaseMessages.getString( PKG, "SwitchCase.Exception.UnableToFindFieldName", meta
        .getFieldname() ) );
    }

    data.inputValueMeta = getInputRowMeta().getValueMeta( data.fieldIndex );

    try {
      StepIOMetaInterface ioMeta = meta.getStepIOMeta();

      // There is one or many case target for each target stream.
      // The ioMeta object has one more target stream for the default target though.
      //
      List<StreamInterface> targetStreams = ioMeta.getTargetStreams();
      for ( int i = 0; i < targetStreams.size(); i++ ) {
        SwitchCaseTarget target = (SwitchCaseTarget) targetStreams.get( i ).getSubject();
        if ( target == null ) {
          break; // Skip over default option
        }
        if ( target.caseTargetStep == null ) {
          throw new KettleException( BaseMessages.getString(
            PKG, "SwitchCase.Log.NoTargetStepSpecifiedForValue", target.caseValue ) );
        }

        RowSet rowSet = findOutputRowSet( target.caseTargetStep.getName() );
        if ( rowSet == null ) {
          throw new KettleException( BaseMessages.getString(
            PKG, "SwitchCase.Log.UnableToFindTargetRowSetForStep", target.caseTargetStep ) );
        }

        try {
          Object value =
            data.valueMeta.convertDataFromString(
              target.caseValue, data.stringValueMeta, null, null, ValueMetaInterface.TRIM_TYPE_NONE );

          // If we have a value and a rowset, we can store the combination in the map
          //
          if ( data.valueMeta.isNull( value ) ) {
            data.nullRowSetSet.add( rowSet );
          } else {
            data.outputMap.put( value, rowSet );
          }
        } catch ( Exception e ) {
          throw new KettleException( BaseMessages.getString(
            PKG, "SwitchCase.Log.UnableToConvertValue", target.caseValue ), e );
        }
      }

      if ( meta.getDefaultTargetStep() != null ) {
        RowSet rowSet = findOutputRowSet( meta.getDefaultTargetStep().getName() );
        if ( rowSet != null ) {
          data.defaultRowSetSet.add( rowSet );
          if ( data.nullRowSetSet.isEmpty() ) {
            data.nullRowSetSet.add( rowSet );
          }
        }
      }
    } catch ( Exception e ) {
      throw new KettleException( e );
    }
  }
}