Workbook workbook = new Workbook();

//Get the first default sheet
Worksheet sheet = workbook.getWorksheets().get(0);

//Add Watermark
Shape wordart = sheet.getShapes().addTextEffect(MsoPresetTextEffect.TEXT_EFFECT_1,
"CONFIDENTIAL", "Arial Black", 50, false, true
, 18, 8, 1, 1, 130, 800);

//Get the fill format of the word art
MsoFillFormat wordArtFormat = wordart.getFillFormat();

//Set the color
wordArtFormat.setForeColor(Color.getRed());

//Set the transparency
wordArtFormat.setTransparency(0.9);

//Make the line invisible
MsoLineFormat lineFormat = wordart.getLineFormat();
lineFormat.setVisible(false);

//Save the file
workbook.save(dataPath + "AsposeWatermark_Out.xls");