[JAVA] ExceptionConverter: java.io.IOException: The document has no pages.

ExceptionConverter: java.io.IOException: The document has no pages.
 at com.itextpdf.text.pdf.PdfPages.writePageTree(PdfPages.java:113)
 at com.itextpdf.text.pdf.PdfWriter.close(PdfWriter.java:1214)
 at com.itextpdf.text.pdf.PdfDocument.close(PdfDocument.java:768)
 at com.itextpdf.text.Document.close(Document.java:398)

StringReader strReader = new StringReader(html);
List<Element> objects = HTMLWorker.parseToList(strReader, styles, interfaceProps);

if (objects != null && objects.size() > 0) {
    int objectCount = objects.size();
    for (int i=0; i<objectCount; i++) {
        document.add((Element)objects.get(i));
    }
} else {

    // IOException: The document has no pages 방지
    document.add(new Chunk(“”));
}

document.close();