I want to add a watermark to the existing pdf using PdfPageEvent
but when I try to do that, it's not working as I want.
here is my code,
private void addWatermark(Uri fileUri) {
InputStream inputStream = getContentResolver().openInputStream(fileUri);
PdfReader reader = new PdfReader(inputStream);
Document document = new Document(PageSize.A4);
PdfWriter writer = PdfWriter.getInstance(document, new FileOutputStream(expPDF));
writer.setBoxSize("page", document.getPageSize());
writer.setPageEvent(watermarkPageEvent);
document.open();
PdfContentByte cb = writer.getDirectContent();
for (int i = 1; i <= reader.getNumberOfPages(); i ) {
PdfImportedPage page = writer.getImportedPage(reader, i);
cb.addTemplate(page, 0, 0);
document.newPage();
}
document.close();
}
PDFPageEventHelper
static class WatermarkPageEvent extends PdfPageEventHelper {
private static final String TAG = "WatermarkPageEvent__";
String text = "Testing";
int textSize = 20;
BaseColor textColor = BaseColor.BLACK;
Font.FontFamily fontFamily;
int fontStyle = Font.BOLD;
int rotate = 0;
Font font;
Phrase phrase;
boolean isW;
public WatermarkPageEvent() {
fontFamily = Font.FontFamily.HELVETICA;
font = new Font(fontFamily, textSize, fontStyle, textColor);
phrase = new Phrase(new Anchor(text));
phrase.setFont(font);
}
@Override
public void onOpenDocument(PdfWriter writer, Document document) {
super.onOpenDocument(writer, document);
}
@Override
public void onEndPage(PdfWriter writer, Document document) {
Rectangle rectangle = writer.getBoxSize("page");
ColumnText.showTextAligned(writer.getDirectContentUnder(),//
Element.ALIGN_CENTER,//
phrase,//
(rectangle.getWidth() / 2f), // want to add watermark in center
(rectangle.getHeight() / 2f), //
rotate);//
}
public void addText(String toString) {
text = toString;
phrase.add(new Anchor(text));
}
}
CodePudding user response:
You can add watermarks even without using PdfPageEvent in iText 5.5.X. Please refer to the following working example.
import com.itextpdf.text.DocumentException;
import com.itextpdf.text.Element;
import com.itextpdf.text.Font;
import com.itextpdf.text.Font.FontFamily;
import com.itextpdf.text.Phrase;
import com.itextpdf.text.pdf.ColumnText;
import com.itextpdf.text.pdf.PdfContentByte;
import com.itextpdf.text.pdf.PdfGState;
import com.itextpdf.text.pdf.PdfReader;
import com.itextpdf.text.pdf.PdfStamper;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
public class TransparentWatermark {
public static final String SRC = "src/main/resources/nanobi/input_watermark.pdf";
public static final String DEST = "src/main/resources/nanobi/output_watermark.pdf";
public static void main(String[] args) throws IOException, DocumentException {
File file = new File(DEST);
file.getParentFile().mkdirs();
new TransparentWatermark().manipulatePdf(SRC, DEST);
}
public void manipulatePdf(String src, String dest) throws IOException, DocumentException {
PdfReader reader = new PdfReader(src);
PdfStamper stamper = new PdfStamper(reader, new FileOutputStream(dest));
PdfContentByte under = stamper.getUnderContent(1);
Font f = new Font(FontFamily.HELVETICA, 15);
Phrase p = new Phrase("This watermark is added UNDER the existing content", f);
ColumnText.showTextAligned(under, Element.ALIGN_CENTER, p, 297, 550, 0);
PdfContentByte over = stamper.getOverContent(1);
p = new Phrase("This watermark is added ON TOP OF the existing content", f);
ColumnText.showTextAligned(over, Element.ALIGN_CENTER, p, 297, 500, 0);
p = new Phrase("This TRANSPARENT watermark is added ON TOP OF the existing content", f);
over.saveState();
PdfGState gs1 = new PdfGState();
gs1.setFillOpacity(0.5f);
over.setGState(gs1);
ColumnText.showTextAligned(over, Element.ALIGN_CENTER, p, 297, 450, 0);
over.restoreState();
stamper.close();
reader.close();
}
}
Please refer to the example here at iText knowledge base on how to add watermarks with events https://kb.itextpdf.com/home/it5kb/examples/page-events-for-watermarking