How to open a file after successfully writing it to disk storage

Question

So I have this method to write the response result from my server which is written to storage.

private boolean writeResponseBodyToDisk(ResponseBody body) {
        try {
            File filesDir = getContext().getExternalFilesDir(Environment.DIRECTORY_DOWNLOADS);
            assert filesDir != null;

            downloadedFile = new File(filesDir,
                    "file_name" + ".pdf");

            InputStream inputStream = null;
            OutputStream outputStream = null;

            try {
                byte[] fileReader = new byte[4096];

                long fileSize = body.contentLength();
                long fileSizeDownloaded = 0;

                inputStream = body.byteStream();
                outputStream = new FileOutputStream(downloadedFile);

                while (true) {
                    int read = inputStream.read(fileReader);

                    if (read == -1) {
                        break;
                    }

                    outputStream.write(fileReader, 0, read);

                    fileSizeDownloaded += read;
                }

                outputStream.flush();

                // This is how i call openPDF() method
                openPDF(Uri.fromFile(downloadedFile));

                return true;
            } catch (IOException e) {
                return false;
            } finally {
                if (inputStream != null) {
                    inputStream.close();
                }

                if (outputStream != null) {
                    outputStream.close();
                }
            }
        } catch (IOException e) {
            return false;
        }
    }

But how do you open this file immediately after successfully writing it to disk storage? I have tried to read the documentation entitled Access documents and other files from shared storage and Access app-specific files but the explanation does not lead to the information I need.

From what i read, I think it takes a differentiator to access storage from a different android version, like

 if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.GINGERBREAD) {
     // only for gingerbread and newer versions
 }

I have tried this method but it doesn't work..

    private void openPDF(Uri uri) {
        try {
            Intent testIntent = new Intent("com.adobe.reader");
            testIntent.setType("application/pdf");
            testIntent.setAction(Intent.ACTION_VIEW);
            Uri uri = Uri.fromFile(uri);
            testIntent.setDataAndType(uri, "application/pdf");
            startActivity(testIntent);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

Have a look at this example https://stackoverflow.com/a/24748227/1133011 — David Kroukamp, Nov 18 '20 at 05:13
You read it by opening a fileinputstream for the file and then read from the stream like you did with the other inputstream. `FileInputStream fis = new FileInputStream(downlodedFile);`. — blackapps, Nov 18 '20 at 08:24
`I have tried this method but it doesn't work..` Indeed. But why dont you mention the errors you encounter? There are several at first sight. — blackapps, Nov 18 '20 at 08:28
@blackapps I know this is wrong, so actually I just wrote the storage path of that file into the Uri parameter `openPdf()` method .. — Muhammad Faisal, Nov 18 '20 at 08:44
`why dont you mention the errors you encounter? There are several at first sight. ` — blackapps, Nov 18 '20 at 08:53
@blackapps I have entered the code that I used to call the `openPDF ()` method, and why didn't I mention the error that came up, it's because there really wasn't an error or the code was running.. — Muhammad Faisal, Nov 18 '20 at 09:03
`Uri uri = Uri.fromFile(uri);` Hard to believe that that statement compiles. But anyhow: you should instead use a FileProvider to serve your file as since Android 7/N you will have a FileUriExposedException now. — blackapps, Nov 18 '20 at 09:21
@blackapps okay that means I have to set up two different methods between Android 7 / N? Do you have any reference examples of applications where one of them is successful? — Muhammad Faisal, Nov 18 '20 at 09:43

How to open a file after successfully writing it to disk storage

0 Answers0