This technical tip explains how to add a watermark to a document  in Microsoft Word document inside Android Applications.  Sometimes you need to insert a watermark into a Word document, for instance if you would like to print a draft document or mark it as confidential. In Microsoft Word, you can quickly insert a watermark using the Insert Watermark command. Not many people using this command realize that such “watermark” is just a shape with text inserted into a header or footer and positioned in the centre of the page. While Aspose.Words doesn't have a single insert watermark command like Microsoft Word, it is very easy to insert any shape or image into a header or footer and thus create a watermark of any imaginable type.

The code below inserts a watermark into a Word document.

package AddWatermark;

import java.awt.Color;
import java.io.File;
import java.net.URI;

import com.aspose.words.Document;
import com.aspose.words.Shape;
import com.aspose.words.ShapeType;
import com.aspose.words.RelativeHorizontalPosition;
import com.aspose.words.RelativeVerticalPosition;
import com.aspose.words.WrapType;
import com.aspose.words.VerticalAlignment;
import com.aspose.words.HorizontalAlignment;
import com.aspose.words.Paragraph;
import com.aspose.words.Section;
import com.aspose.words.HeaderFooterType;
import com.aspose.words.HeaderFooter;



public class Program
{
    public static void main(String[] args) throws Exception
    {
        // Sample infrastructure.
        URI exeDir = Program.class.getResource("").toURI();
        String dataDir = new File(exeDir.resolve("../../Data")) + File.separator;

        Document doc = new Document(dataDir + "TestFile.doc");
        insertWatermarkText(doc, "CONFIDENTIAL");
        doc.save(dataDir + "TestFile Out.doc");
    }

    /**
     * Inserts a watermark into a document.
     *
     * @param doc The input document.
     * @param watermarkText Text of the watermark.
     */
    private static void insertWatermarkText(Document doc, String watermarkText) throws Exception
    {
        // Create a watermark shape. This will be a WordArt shape.
        // You are free to try other shape types as watermarks.
        Shape watermark = new Shape(doc, ShapeType.TEXT_PLAIN_TEXT);

        // Set up the text of the watermark.
        watermark.getTextPath().setText(watermarkText);
        watermark.getTextPath().setFontFamily("Arial");
        watermark.setWidth(500);
        watermark.setHeight(100);
        // Text will be directed from the bottom-left to the top-right corner.
        watermark.setRotation(-40);
        // Remove the following two lines if you need a solid black text.
        watermark.getFill().setColor(Color.GRAY); // Try LightGray to get more Word-style watermark
        watermark.setStrokeColor(Color.GRAY); // Try LightGray to get more Word-style watermark

        // Place the watermark in the page center.
        watermark.setRelativeHorizontalPosition(RelativeHorizontalPosition.PAGE);
        watermark.setRelativeVerticalPosition(RelativeVerticalPosition.PAGE);
        watermark.setWrapType(WrapType.NONE);
        watermark.setVerticalAlignment(VerticalAlignment.CENTER);
        watermark.setHorizontalAlignment(HorizontalAlignment.CENTER);

        // Create a new paragraph and append the watermark to this paragraph.
        Paragraph watermarkPara = new Paragraph(doc);
        watermarkPara.appendChild(watermark);

        // Insert the watermark into all headers of each document section.
        for (Section sect : doc.getSections())
        {
            // There could be up to three different headers in each section, since we want
            // the watermark to appear on all pages, insert into all headers.
            insertWatermarkIntoHeader(watermarkPara, sect, HeaderFooterType.HEADER_PRIMARY);
            insertWatermarkIntoHeader(watermarkPara, sect, HeaderFooterType.HEADER_FIRST);
            insertWatermarkIntoHeader(watermarkPara, sect, HeaderFooterType.HEADER_EVEN);
        }
    }

    private static void insertWatermarkIntoHeader(Paragraph watermarkPara, Section sect, int headerType) throws Exception
    {
        HeaderFooter header = sect.getHeadersFooters().getByHeaderFooterType(headerType);

        if (header == null)
        {
            // There is no header of the specified type in the current section, create it.
            header = new HeaderFooter(sect.getDocument(), headerType);
            sect.getHeadersFooters().add(header);
        }

        // Insert a clone of the watermark into the header.

        header.appendChild(watermarkPara.deepClone(true));

    }

}