What causes "The width of a line can not be 0 or less." in pentaho/pentaho-kettle?

Enter a positive integer line width matching the fixed-width file layout (e.g. 80) in the dialog's Line width box.

pentaho/pentaho-kettle · error · IOException

The width of a line can not be 0 or less.

Error message

The width of a line can not be 0 or less.

What it means

FixedInputDialog's OK/preview path writes the dialog's settings into a FixedFileInputMeta and validates that the configured line width parses as a positive integer. A width of 0 or less throws IOException 'The width of a line can not be 0 or less.' because fixed-width input cannot slice fields without a positive line width.

Solutions

Enter a positive integer line width matching the fixed-width file layout (e.g. 80) in the dialog's Line width box.
Remove any non-numeric characters or units from the width field.
Use 'Get fields' after setting a valid width so field positions can be computed.
If loading an existing step, reopen it and re-set the width lost during import/upgrade.

Example fix

// before
oneMeta.setLineWidth( "0" ); // throws IOException
// after
oneMeta.setLineWidth( "80" ); // positive width

Defensive patterns

Strategy: validation

Validate before calling

int lineWidth = 0;
try { lineWidth = Integer.parseInt( oneMeta.getLineWidth() ); } catch ( NumberFormatException e ) { /* handle */ }
if ( lineWidth <= 0 ) {
  // prompt user to enter a positive width before proceeding
}

Try / catch

try {
  getInfo( oneMeta );
} catch ( IOException e ) {
  if ( e.getMessage().contains( "width of a line" ) ) {
    // focus the line-width field and ask the user for a positive integer
  }
}

Prevention

Always set a positive numeric line width before previewing or confirming the dialog.
Never include units or symbols in the width field.
Re-check width settings after importing or upgrading fixed-input steps.

When it happens

Trigger: Clicking OK or preview on the Fixed file input dialog when the 'line width' field is empty, 0, negative, or non-numeric (parseInt throws NumberFormatException at Integer.parseInt(oneMeta.getLineWidth())).

Common situations: User left the line-width field at its default 0 before configuring fields; copy-pasted a value with units ('80px'); a saved configuration lost its width value after an upgrade or import.

Understand the failure class

Background: "value must be between 0 and 1" / "out of range" / "must not be negative" errors: fixing range-validation failures across open-source libraries — this error's family across 42 libraries.

Related errors

AI-assisted analysis of pentaho/pentaho-kettle@f3058517a1 (2026-09-13). Data as JSON: /api/errors/b1fa09ea48031330. Report an issue: GitHub.

Appendix: source

Thrown at ui/src/main/java/org/pentaho/di/ui/trans/steps/fixedinput/FixedInputDialog.java:833

        shell, BaseMessages.getString( PKG, "FixedInputDialog.ErrorShowingFixedWizard.DialogTitle" ),
        BaseMessages.getString( PKG, "FixedInputDialog.ErrorShowingFixedWizard.DialogMessage" ), e );
    }
  }

  // Grab the first x lines from the given file...
  //
  private List<String> getFirst( FixedInputMeta meta, int limit ) throws IOException, KettleValueException {

    List<String> lines = new ArrayList<String>();

    FixedInputMeta oneMeta = new FixedInputMeta();
    getInfo( oneMeta );

    // Add a single field with the width of the line...
    //
    int lineWidth = Integer.parseInt( oneMeta.getLineWidth() );
    if ( lineWidth <= 0 ) {
      throw new IOException( "The width of a line can not be 0 or less." );
    }

    oneMeta.allocate( 1 );

    FixedFileInputField field = new FixedFileInputField();
    field.setName( "Field1" );
    field.setType( ValueMetaInterface.TYPE_STRING );
    field.setWidth( lineWidth );
    //CHECKSTYLE:Indentation:OFF
    oneMeta.getFieldDefinition()[0] = field;

    TransMeta previewMeta =
      TransPreviewFactory.generatePreviewTransformation( transMeta, oneMeta, wStepname.getText() );

    TransPreviewProgressDialog progressDialog =
      new TransPreviewProgressDialog(
        shell, previewMeta, new String[] { wStepname.getText() }, new int[] { limit } );
    progressDialog.open();

View on GitHub (pinned to f3058517a1)