如何在Android中将图像文件转换为pdf文件

我正在尝试在 Android 应用程序中将图像文件（jpg）转换为 pdf 文件。我用过itextpdf罐子和机器人文本罐。都不适合我。下面是使用时的代码itextpdf.

Document document = new Document();

String directoryPath = Environment.getExternalStorageDirectory().toString();

File newPdfFile = new File(directoryPath, "textview8.pdf");

FileOutputStream fileOutputStream = null;

try {
    fileOutputStream = new FileOutputStream(newPdfFile);
} catch (FileNotFoundException fnfe) {
    Log.w(TAG, "# Exception caz of fileOutputStream : " + fnfe);
}

BufferedOutputStream bufferedOutputStream = new BufferedOutputStream(fileOutputStream);

try {
    PdfWriter.getInstance(document, bufferedOutputStream);
} catch (DocumentException de) {
    Log.w(TAG, "# Exception caz of PdfWriter.getInstance : " + de);
}

document.open(); 

Image image = null;

try {
    image = Image.getInstance(directoryPath + File.separator + "textview1.JPEG");
} catch (BadElementException bee) {
    Log.w(TAG, "# First exception caz of image : " + bee);
} catch (MalformedURLException mue) {
    Log.w(TAG, "# Second exception caz of image : " + mue);
} catch (IOException ioe) {
    Log.w(TAG, "# Third exception caz of image : " + ioe);
}

try {
    document.add(image);
} catch (DocumentException de) {
    Log.w(TAG, "# Exception caz of document.add : " + de);
}

try {
    bufferedOutputStream.flush();
    bufferedOutputStream.close();

    fileOutputStream.flush();
    fileOutputStream.close();

} catch (IOException ioe) {
    Log.w(TAG, "# Exception caz of bufferedOutputStream.flush : " + ioe);
}

document.close();

这给了我一个错误NullPointerException因为代码行document.close();

当我评论该行并运行程序时，它给出了以下错误。

Could not find class 'com.itextpdf.awt.PdfPrinterGraphics2D', referenced from method com.itextpdf.text.pdf.PdfContentByte.createPrinterGraphicsShapes

但他们告诉找不到的类已经在 jar 文件中，这意味着com.itextpdf.awt.PdfPrinterGraphics2D已存在于项目中。

我已经添加了itextpdf-5.1.3.jar也到构建路径。我用模拟器和真实设备尝试了这一点。

无法弄清楚我做错了什么。请帮忙...

只需简单地这样做就可以正常工作

Document document=new Document();
String dirpath=android.os.Environment.getExternalStorageDirectory().toString();
PdfWriter.getInstance(document,new FileOutputStream(dirpath+"/imagedemo.pdf"));
document.open();
Image im=Image.getInstance(dirpath+"/"+"logo.png");  // Replace logo.png with your image name with extension 
document.add(im);
document.close();