pentaho/pentaho-kettle · error · KettleException

Error writing line :" + e.toString() (logged)…

Error message

Error writing line :" + e.toString() (logged), KettleException( e )

What it means

ExcelWriterStep.writeNextLine catches any exception thrown while writing a row of data to the sheet, logs 'Error writing line :<exception>', and rethrows it as a KettleException to fail the step. It means cell/sheet write operations for the current input row failed.

Solutions

1. Read the logged 'Error writing line :...' entry — it contains the underlying exception with row details.
2. Check the input row's field values and types against the step's field mapping (content/types).
3. If formulas are enabled, verify formula strings are valid Excel syntax.
4. For XLS output, confirm no XLSX-only features (e.g. cell comments, >65536 rows, >256 columns) are used.
5. Log or preview the failing row (add a 'Get rows' count / log row) to identify the offending data.

Example fix

// before: null field value written as-is causes POI failure
sheet.addCell( new jxl.write.Number( col, row, numericValue ) );
// after: guard conversions
if ( value == null ) {
  sheet.addCell( new jxl.write.Blank( col, row ) );
} else {
  sheet.addCell( new jxl.write.Number( col, row, numericValue ) );
}

// before running, validate the row fields written to Excel
rowMeta.getFieldNames(); // confirm mapping matches input
if ( value == null || String.valueOf( value ).length() > 32767 ) {
  throw new IllegalArgumentException( "Cell content exceeds Excel limit or is null" );
}

boolean isExcelWritable( Object v ) { return v != null && !( v instanceof Double && !Double.isFinite( (Double) v ) ); }

try { writeNextLine( row ); } catch ( KettleException e ) { logError( "Failed on row " + rowNum + ": " + e.getMessage(), e ); setErrors( 1 ); }

When it happens

Trigger: writeNextLine() throws while creating/writing cells into data.sheet (e.g. invalid cell type/value, sheet write error, POI internal failure) for the current row; posX/posY advance only on success.

Common situations: Field values incompatible with the chosen Excel format (e.g. oversized strings, invalid formula content); unsupported cell comment/content on the current sheet type; POI limitations with the target workbook (XLS vs XLSX features); extremely wide rows exceeding column limits.

Understand the failure class

Background: "failed to write file", "Could not save figure", "Error saving remote file" — file write failed: causes and fixes across languages and libraries — this error's family across 38 libraries.

Related errors

• KettleException( e )
• Bounds of this rule are not numeric: lowerBound=
• ConnectionFileObject.PVFSRoot.UnsupportedOperation
• ConnectionFileObject.UndefinedConnection
• Could not convert to the given local format.

AI-assisted analysis of pentaho/pentaho-kettle@f3058517a1 (2026-09-13). Data as JSON: /api/errors/8b40d4dec1b51617. Report an issue: GitHub.

Appendix: source

Thrown at plugins/excel/core/src/main/java/org/pentaho/di/trans/steps/excelwriter/ExcelWriterStep.java:386

          writeField( r[i], data.inputRowMeta.getValueMeta( i ), null, xlsRow, data.posX++, r, i, false );
        }
      } else {
        /*
         * Only write the fields specified!
         */
        for ( int i = 0; i < meta.getOutputFields().length; i++ ) {
          Object v = r[data.fieldnrs[i]];
          writeField( v, data.inputRowMeta.getValueMeta( data.fieldnrs[i] ), meta.getOutputFields()[i], xlsRow,
            data.posX++, r, i, false );
        }

      }
      // go to the next line
      data.posX = data.startingCol;
      data.posY++;
    } catch ( Exception e ) {
      logError( "Error writing line :" + e.toString() );
      throw new KettleException( e );
    }
  }

  private Comment createCellComment( String author, String comment ) {
    // comments only supported for XLSX
    if ( data.sheet instanceof XSSFSheet ) {
      CreationHelper factory = data.wb.getCreationHelper();
      Drawing<?> drawing = data.sheet.createDrawingPatriarch();

      ClientAnchor anchor = factory.createClientAnchor();
      Comment cmt = drawing.createCellComment( anchor );
      RichTextString str = factory.createRichTextString( comment );
      cmt.setString( str );
      cmt.setAuthor( author );
      return cmt;
    }
    return null;
  }

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