Itext7 generate pdf with Exception “Pdf indirect object belongs to other PDF document. Copy object to current pdf document.”

Question

i want to generate a pdf with itext 7,but some wrong happens to us:

com.itextpdf.kernel.PdfException: Pdf indirect object belongs to other PDF document. Copy         


        

Answer 1

I have experienced the same problem myself (and it took me hours to discover what I was doing wrong). As it turns out, you can use a specific PdfFont instance for only one document. As soon as you use a PdfFont instance it is linked to that document, and you can no longer use it in another document.

For instance:

class ThisGoesWrong {

    protected PdfFont font;

    public ThisGoesWrong() {
        font = PdfFontFactory.createFont(...);
    }

    public void createPdf() {
        ...
        Paragraph p = new Paragraph("test").setFont(font);
        document.add(p);
        ...
    }
}

The class ThisGoesWrong creates a correct PDF the first time you call createPdf(), but it shows the exception you have when you call it a second time.

I discovered that this solves the problem:

class ThisWorksOK {

    public ThisWorksOK() {
    }

    public void createPdf() {
        ...
        PdfFont font = PdfFontFactory.createFont(...);
        Paragraph p = new Paragraph("test").setFont(font);
        document.add(p);
        ...
    }
}

I don't know if this is a bug (it certainly feels like a bug), so I will create an internal ticket at iText Group.