iText生成一个空核心

Question

我使用iText（5.5.8）从对象列表生成pdf。首先，我只是在列表中添加一个元素（com.itextpdf.text.List），生成的pdf非常好。

现在，我已经改进了一些pdf创建的代码，但它创建了一个空核，我只有标题（我没有修改）。

//CORE
Paragraph itin = new Paragraph();  

// add a list
Paragraph list = createList(itin, listOfPackages);

// now add all this to the document
document.add(list);

document.close();

这是列表的创建

private static Paragraph createList(Paragraph paragraph, ArrayList<Package> loP) {
    List list = new List(true, false, 12);
    int i = 0;
    while(i<loP.size()){

        Paragraph info = new Paragraph();

        String bufferPdf;

        bufferPdf = "ICU: ";
        bufferPdf = bufferPdf + loP.get(i).getIcu()+ " ";
        info.add(new Paragraph(bufferPdf));
        addEmptyLine(info, 1);

        bufferPdf = "Adresse: ";
        bufferPdf = loP.get(i).getAddress().getStreet() + ", ";
        bufferPdf = bufferPdf + loP.get(i).getAddress().getNumber() + " ";
        bufferPdf = bufferPdf + loP.get(i).getAddress().getBox() + ", ";
        info.add(new Paragraph(bufferPdf));

        bufferPdf = loP.get(i).getAddress().getPostalCode() + " ";
        bufferPdf = bufferPdf + loP.get(i).getAddress().getCity() + ", ";
        info.add(new Paragraph(bufferPdf));

        bufferPdf = loP.get(i).getAddress().getCountry() + " ";
        info.add(new Paragraph(bufferPdf));
        addEmptyLine(info, 1);

        bufferPdf = "Poids déclaré: ";
        bufferPdf = bufferPdf + String.valueOf(loP.get(i).getWeightDecl()) + " Kg";
        info.add(new Paragraph(bufferPdf));

        bufferPdf = "Poids réel: ";
        bufferPdf = bufferPdf + String.valueOf(loP.get(i).getRealWeight()) + " Kg";
        info.add(new Paragraph(bufferPdf));

        bufferPdf = "Hauteur: ";
        bufferPdf = bufferPdf + String.valueOf(loP.get(i).getHeight()) + " cm";
        info.add(new Paragraph(bufferPdf));

        bufferPdf = "Circomférence: ";
        bufferPdf = bufferPdf + String.valueOf(loP.get(i).getCircumference()) + " cm";
        info.add(new Paragraph(bufferPdf));

        list.add(info);
        i++;
    }
    paragraph.add(list);

    return paragraph;
  }

Package列表不为空也不为null。 （它不是＆＃34;包＆＃34;来自java，Package在这里引用另一个对象。