// PNG 转 PDF

public static String PngToPdf(String pngUrl) {
String pdfUrl = "";
Document doc = null;
try {
doc = new Document(null, 0, 0, 0, 0);
pdfUrl = pngUrl.replaceAll("(?i).png", ".PDF");
PdfWriter.getInstance(doc, new FileOutputStream(pdfUrl));
Image img = Image.getInstance(pngUrl); // 原来的图片的路径
doc.setPageSize(new Rectangle(img.getWidth(), img.getHeight()));
doc.open();
doc.add(img);
doc.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (DocumentException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return pdfUrl;
}