Question

我尝试将空格(" ")的空白单元格添加到我的pdf文件中。即

 PdfPCell blankCell = ContentHandler.getNormalCell(" ", language,fontsize);

它会抛出此错误

Message: java.lang.NullPointerException
         com.itextpdf.text.DocumentException: java.lang.NullPointerException
         at com.itextpdf.text.pdf.PdfDocument.add(PdfDocument.java:727)
         at com.itextpdf.text.Document.add(Document.java:282)

然后我从细胞中移除了空间..即

PdfPCell blankCell = ContentHandler.getNormalCell("", language,fontsize);

我以这种方式解决了我的问题，但是pdf很糟糕。

有人可以帮助我吗，除了我正在做的事情之外，有没有可用的解决方案

编辑：

public static PdfPCell getNormalCell(String string, String language, float size) throws DocumentException, IOException {
    // TODO Auto-generated method stub
    Font f =  new Font();
    if(string!=null && !"".equals(string)){
        f = getFontForThisLanguage(language);
    }
    if(size==-1)  //Using a condition to make color RED as per need in view report
    {
    f.setColor(BaseColor.RED);
    }

    f.setSize(size);

    Chunk chunk = new Chunk(new String(string.getBytes(), "UTF-8"),f);

    PdfPCell pdfCell1 = new PdfPCell(new Phrase(string, f));
    pdfCell1.setHorizontalAlignment(Element.ALIGN_LEFT);

    return pdfCell1;

}

Answer 1

首先回答您的问题：我创建了一个名为CellMethod的示例，我可以完美地将" "添加到PdfPCell而不会导致NullPointerException。这是我的代码：

public void createPdf(String dest) throws IOException, DocumentException {
    Document document = new Document();
    PdfWriter.getInstance(document, new FileOutputStream(dest));
    document.open();
    PdfPTable table = new PdfPTable(2);
    table.addCell("Winansi");
    table.addCell(getNormalCell("Test", null, 12));
    table.addCell("Winansi");
    table.addCell(getNormalCell("Test", null, -12));
    table.addCell("Greek");
    table.addCell(getNormalCell("\u039d\u03cd\u03c6\u03b5\u03c2", "greek", 12));
    table.addCell("Czech");
    table.addCell(getNormalCell("\u010c,\u0106,\u0160,\u017d,\u0110", "czech", 12));
    table.addCell("Test");
    table.addCell(getNormalCell(" ", null, 12));
    table.addCell("Test");
    table.addCell(getNormalCell(" ", "greek", 12));
    table.addCell("Test");
    table.addCell(getNormalCell(" ", "czech", 12));
    document.add(table);
    document.close();
}

public static PdfPCell getNormalCell(String string, String language, float size)
        throws DocumentException, IOException {
    if(string != null && "".equals(string)){
        return new PdfPCell();
    }
    Font f  = getFontForThisLanguage(language);
    if(size < 0) {
        f.setColor(BaseColor.RED);
        size = -size;
    }
    f.setSize(size);
    PdfPCell cell = new PdfPCell(new Phrase(string, f));
    cell.setHorizontalAlignment(Element.ALIGN_LEFT);
    return cell;
}
public static Font getFontForThisLanguage(String language) {
    if ("czech".equals(language)) {
        return FontFactory.getFont(FONT, "Cp1250", true);
    }
    if ("greek".equals(language)) {
        return FontFactory.getFont(FONT, "Cp1253", true);
    }
    return FontFactory.getFont(FONT, null, true);
}

可在此处找到生成的PDF：cell_method.pdf

现在关于评论。就好像你不想接受你的代码写得不好。相反，您声称iText存在问题。这是一个坏工匠，责备他的工具。

您尝试改进方法，但让我们看看您的方法并添加一些注释：

public static PdfPCell getNormalCell(String string, String language, float size)
    throws DocumentException, IOException {
    // The next line will create an instance of Helvetica, 12pt.
    Font f =  new Font();
    // I don't understand this check. Why is it important to check string here?
    if(string!=null && !"".equals(string)){
        // are you sure you didn't want to check if language is not null?
        f = getFontForThisLanguage(language);
        // we have no idea what getFontForThisLanguage is doing
        // what if language is null, does it throw an exception?
    }
    // This is ridiculous. See the next comment to find out why
    if(size==-1)  //Using a condition to make color RED as per need in view report
    {
    f.setColor(BaseColor.RED);
    }
    // In some situations, you are setting the font size to -1, that doesn't make sense
    f.setSize(size);
    // This line doesn't make sense either.
    // (1.) string should already be in unicode.
    //      why are you getting the bytes and creating a UTF-8 string?
    // (2.) why are you creating this chunk object? you never use it
    Chunk chunk = new Chunk(new String(string.getBytes(), "UTF-8"),f);
    // See: you're creating a Phrase with string, you don't use chunk!
    PdfPCell pdfCell1 = new PdfPCell(new Phrase(string, f));
    pdfCell1.setHorizontalAlignment(Element.ALIGN_LEFT);
    return pdfCell1;
}

请与我的方法版本进行比较。

iText库异常抛出添加空格Cell和空格

1 个答案: