Java insert multiple text watermarks to Word document

import com.spire.doc.Document;
import com.spire.doc.FileFormat;
import com.spire.doc.HeaderFooter;
import com.spire.doc.Section;
import com.spire.doc.documents.Paragraph;
import com.spire.doc.documents.ShapeLineStyle;
import com.spire.doc.documents.ShapeType;
import com.spire.doc.fields.ShapeObject;
import java.awt.*;

public class WordWatermark {

    public static void main(String[] args) {

        //Load the sample document
        Document doc = new Document();
        doc.loadFromFile("Sample.docx");
        //Add WordArt shape and set the size
        ShapeObject shape = new ShapeObject(doc, ShapeType.Text_Plain_Text);
        shape.setWidth(60);
        shape.setHeight(20);
        //Set the text, position and sytle for the wordart
        shape.setVerticalPosition(30);
        shape.setHorizontalPosition(20);
        shape.setRotation(315);
        shape.getWordArt().setText("Confidential");
        shape.setFillColor(Color.red);
        shape.setLineStyle(ShapeLineStyle.Single);
        shape.setStrokeColor(new Color(192, 192, 192, 255));
        shape.setStrokeWeight(1);

        Section section;
        HeaderFooter header;
        for (int n = 0; n < doc.getSections().getCount(); n++) {
            section = doc.getSections().get(n);
            //Get the header of section
            header = section.getHeadersFooters().getHeader();
            Paragraph paragraph1;
            for (int i = 0; i < 4; i++) {
                //Add the hearder to the paragraph
                paragraph1 = header.addParagraph();
                for (int j = 0; j < 3; j++) {
                    //copy the word are and add it to many places
                    shape = (ShapeObject) shape.deepClone();
                    shape.setVerticalPosition(50 + 150 * i);
                    shape.setHorizontalPosition(20 + 160 * j);
                    paragraph1.getChildObjects().add(shape);
                }
            }
        }
        //Save the document to file
        doc.saveToFile("Result.docx", FileFormat.Docx_2013);

    }
}