Saving Byte Array as a PNG file into smb2 server

Question

I'm trying to create an app that will save image from a Byte[] Array as a .png file into my smb2 server, I was able to save a file but it only contains the Array as file name with 0kb size.

Getting image from camera

@SuppressLint("MissingSuperCall")
    @Override
    protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
        if(requestCode == REQUEST_CODE) {
            if (resultCode != RESULT_CANCELED) {
                image = (Bitmap) data.getExtras().get("data");
                ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
                image.compress(Bitmap.CompressFormat.PNG, 100, byteArrayOutputStream);
                bytesCapturedLogbook = byteArrayOutputStream.toByteArray();

                MyCopy my = new MyCopy();
                my.execute(bytesCapturedLogbook);
            }
        }
    }

Class for inserting file into my server

private class MyCopy extends AsyncTask<byte[], String, String> {

        @Override
        protected String doInBackground(byte[]... bytes) {
            String z = "";
            try {

                String url = "smb://000.000.0.000/spm/Image/" + bytes + ".png";

                NtlmPasswordAuthentication auth = new NtlmPasswordAuthentication(
                        null, "********", "**********");
                SmbFile sfile = new SmbFile(url, auth);

                if (!sfile.exists()) {
                    sfile.createNewFile();
                    z = "Created the file for you!!!!";
                } else
                    z = "Already exists at the specified location!!!!";

            } catch (Exception ex) {
                // TODO: handle exception
                z = ex.getMessage().toString();
            }
            return z;
        }

        @Override
        protected void onPreExecute() {
            // TODO Auto-generated method stub


        }

        @Override
        protected void onPostExecute(String r) {
        }


    }

Result inside file explorer

I don't see anywhere that you actually attempt to write any bytes to file. See here for how this could be done: [byte\[\] to file in Java](https://stackoverflow.com/questions/4350084/byte-to-file-in-java) or see [this answer using newer NIO features](https://stackoverflow.com/a/29623982/1270000) — sorifiend, Aug 16 '22 at 06:05
There's no file getting saved, when I tried all the answers from the link you provided. — Ryan Baltazar, Aug 16 '22 at 06:57
doInBackground: java.io.FileNotFoundException: 004920224616080824: open failed: EROFS (Read-only file system) 004920224616080824 is the file name — Ryan Baltazar, Aug 16 '22 at 07:06
It would help if you updated the question with the actions that save the `bytes` parameter of `doBackground`. At present this creates empty file. By the way the parameter is defined as `byte[][]` due to the `...`. — DuncG, Aug 16 '22 at 07:20
https://stackoverflow.com/questions/71394187/take-and-save-photo-to-network-folder-android, I updated my code like this, but I get 'java.io.FileNotFoundException' — Ryan Baltazar, Aug 17 '22 at 06:41
Unfortunately we can't guess which bits of the other question you've copied. I've voted to close (needs debugging details) because your program seems to work exactly as you've described: it intentionally creates an empty file. — DuncG, Aug 17 '22 at 08:01
I'm only a beginner, I really don't know what I supposed to do, hoping someone can help me. — Ryan Baltazar, Aug 18 '22 at 08:30
@Ryan Baltazar I've added suggestions in an answer below which may help, though this question may get closed soon. BTW You've used `bytes + ".png"` as the target file which means you have a weird filename `[[B...`. — DuncG, Aug 18 '22 at 09:09

DuncG · Answer 1 · 2022-08-18T09:05:18.017

Your question may be partly answered in the question you found. It shows file to smbfile copy via byte[]. As you have byte[] already you should adjust the doInBackground(byte[]... bytes) to pass your single byte[] to smbfile something like this:

SmbFileOutputStream outNew = new SmbFileOutputStream(smbFile);
outNew.write(bytes[0]);
outNew.close();

or in later JVM its better with with try-with-resources to clean up for you:

try (SmbFileOutputStream outNew = new SmbFileOutputStream(smbFile)) {
   outNew.write(bytes[0]);
}

Note that I'm not able to test any of the above, and as you've also shown the problem java.io.FileNotFoundException: 004920224616080824: open failed: EROFS then you may be simply trying to write to an invalid location (a path issue?) as it looks like you put the wrong file names into new SmbFile(...).

Saving Byte Array as a PNG file into smb2 server

1 Answers1