Images to pdf android java

ImagesToPdf.java

// Just pass context and list of file
// It will create a PDF file in cache dir
// Add your own logic to share/open PDF
// Works fast and reliable method

// >  - No library needed (Uses android internal android.graphics.pdf.PdfDocument classes)
// >  - Works in background, Doesn''t freeze UI
// >  - No need to declare and grant storage permission :)


    @SuppressLint("StaticFieldLeak")
    public static void createPdf(Context context,ArrayList<File> data){
        File pdfFile = new File(context.getExternalCacheDir().getAbsolutePath() + File.separator + "TemperoryPDF_"+System.currentTimeMillis()+".pdf");
        Toast.makeText(context, "Creating PDF,Please wait..", Toast.LENGTH_SHORT).show();
        new AsyncTask<Void, Void, Void>() {
            @Override
            protected Void doInBackground(Void... voids) {
                PdfDocument document = new PdfDocument();
                try {
                    for(File item:data) {
                        Bitmap bitmap = BitmapFactory.decodeFile(item.getAbsolutePath());
                        PdfDocument.PageInfo pageInfo = new PdfDocument.PageInfo.Builder(bitmap.getWidth(), bitmap.getHeight(), 1).create();
                        PdfDocument.Page page = document.startPage(pageInfo);
                        Canvas canvas = page.getCanvas();
                        Paint paint = new Paint();
                        paint.setColor(Color.parseColor("#ffffff"));
                        canvas.drawPaint(paint);
                        bitmap = Bitmap.createScaledBitmap(bitmap, bitmap.getWidth(), bitmap.getHeight(), true);
                        canvas.drawBitmap(bitmap, 0, 0, null);
                        document.finishPage(page);
                    }
                    document.writeTo(new FileOutputStream(pdfFile));
                } catch (IOException e) {
                    e.printStackTrace();
                }finally {
                    document.close();
                }
                return null;
            }

            @Override
            protected void onPostExecute(Void unused) {
                super.onPostExecute(unused);
                if(pdfFile.exists() && pdfFile.length()>0) {
                    FileUtil.openFile(context, pdfFile.getAbsolutePath()); // See: https://gist.github.com/omkar-tenkale/34d3aa1966653e6949d1ddaee1ba3355
                }else {
                    Toast.makeText(context, "Something went wrong creating the PDF :(", Toast.LENGTH_SHORT).show();
                }
            }
        }.execute();

    }