How to use pdfbox to generate formatted json files

Question

For example，

{
  "appId": "wxa033f083bd79132d",
  "timestamp": 1657699905,
  "nonceStr": "SKIe2Ce352",
  "signature": "20fbc391ed6ed78a3a267c31526239110926a8d1",
  "jsApiList": [
    "updateAppMessageShareData",
    "updateTimelineShareData"
  ]
}

I want to generate pdf file with formatted json，like this：

But I can only generate something like this：

I've tried making it rich text and displaying it inside the pdf, but that doesn't seem to work. And my code

public void testPDF() throws IOException {

        String json = "{\"appId\":\"wxa033f083bd79132d\",\"timestamp\":1657699905,\"nonceStr\":\"SKIe2Ce352\",\"signature\":\"20fbc391ed6ed78a3a267c31526239110926a8d1\",\"jsApiList\":[\"updateAppMessageShareData\",\"updateTimelineShareData\"]}";
        JSONObject jsonObject = JSON.parseObject(json);
        PDDocument document = new PDDocument();
        PDPage pdPage = new PDPage();
        document.addPage(pdPage);
        PDPageContentStream contentStream = new PDPageContentStream(document, pdPage);

        contentStream.beginText();

        contentStream.setFont(PDType1Font.HELVETICA_BOLD, 14);

        contentStream.newLineAtOffset(25, 500);
        contentStream.setLeading(14.5f);
        contentStream.showText("{");
        contentStream.newLine();
        jsonObject.forEach((key, value) -> {
            try {
                contentStream.showText(String.format("\"%s\": %s ", key, value));
                contentStream.newLine();
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        });
        contentStream.showText("}");
        contentStream.newLine();

        contentStream.endText();
        contentStream.close();

        document.save(new File("D:\\new-doc-text.pdf"));

        document.close();

    }

score 0 · Answer 1 · answered Jul 13 '22 at 22:03

PdfBox is very low level Pdf library and if you want to use it to display aligned lines you will have to write whitespace offsetting logic by yourself.

If I were to do it I would use a library like Gson and pretty printing (Pretty-Print JSON in Java) to first parse it line-by-line with whitespaces at front and then print line-by-line.

Another approach is to use a higher level library such as freemarker templates and it's export to PDF. I was using PDFBox and wish I have switched to freemarker much earlier.

How to use pdfbox to generate formatted json files

1 Answers1