File upload from Android (via Multipart Form data)

Most of the time we have to upload our file on server from our Application but when we try to find a way we got all the different ways to do so that make us more confuse. Some says to use some library and some says not to. So here is a method to upload a file to the server via Http Multi-part form data, it doesn’t need any external library and is quiet efficient as well.

Through it you can have a put request to send you file with extra data like in my case I have to send an additional reference tag along with it. So lets start. Here I am supposing that you have a File Adapter and you have selected the file you have to send. Basically you have the URI of the file. If you don’t please follow the link.

public class UploadFile extends AsyncTask<Object, String, String> {

String file_name = "";

@Override

protected String doInBackground(Object[] params) {

try {

String lineEnd = "\r\n";

String twoHyphens = "--";

String boundary = "*****";

int bytesRead, bytesAvailable, bufferSize;

byte[] buffer;

int maxBufferSize = 1024 * 1024;

//todo change URL as per client ( MOST IMPORTANT )

URL url = new URL("http://webkul.com/upload");

HttpURLConnection connection = (HttpURLConnection) url.openConnection();

// Allow Inputs & Outputs.

connection.setDoInput(true);

connection.setDoOutput(true);

connection.setUseCaches(false);

// Set HTTP method to POST.

connection.setRequestMethod("POST");

connection.setRequestProperty("Connection", "Keep-Alive");

connection.setRequestProperty("Content-Type", "multipart/form-data;boundary=" + boundary);

FileInputStream fileInputStream;

DataOutputStream outputStream;

outputStream = new DataOutputStream(connection.getOutputStream());

outputStream.writeBytes(twoHyphens + boundary + lineEnd);

outputStream.writeBytes("Content-Disposition: form-data; name=\"reference\""+ lineEnd);

outputStream.writeBytes(lineEnd);

outputStream.writeBytes("my_refrence_text");

outputStream.writeBytes(lineEnd);

outputStream.writeBytes(twoHyphens + boundary + lineEnd);

outputStream.writeBytes("Content-Disposition: form-data; name=\"uploadFile\";filename=\"" + uri.getLastPathSegment() +"\"" + lineEnd);

outputStream.writeBytes(lineEnd);

fileInputStream = new FileInputStream(uri.getPath());

bytesAvailable = fileInputStream.available();

bufferSize = Math.min(bytesAvailable, maxBufferSize);

buffer = new byte[bufferSize];

// Read file

bytesRead = fileInputStream.read(buffer, 0, bufferSize);

while (bytesRead > 0) {

outputStream.write(buffer, 0, bufferSize);

bytesAvailable = fileInputStream.available();

bufferSize = Math.min(bytesAvailable, maxBufferSize);

bytesRead = fileInputStream.read(buffer, 0, bufferSize);

}

outputStream.writeBytes(lineEnd);

outputStream.writeBytes(twoHyphens + boundary + twoHyphens + lineEnd);

// Responses from the server (code and message)

int serverResponseCode = connection.getResponseCode();

String result = null;

if (serverResponseCode == 200) {

StringBuilder s_buffer = new StringBuilder();

InputStream is = new BufferedInputStream(connection.getInputStream());

BufferedReader br = new BufferedReader(new InputStreamReader(is));

String inputLine;

while ((inputLine = br.readLine()) != null) {

s_buffer.append(inputLine);

}

result = s_buffer.toString();

}

fileInputStream.close();

outputStream.flush();

outputStream.close();

if (result != null) {

Log.d("result_for upload", result);

file_name = getDataFromInputStream(result, "file_name");

}

} catch (Exception e) {

e.printStackTrace();

}

return file_name;

}

So here are you. with this code you can send your file to server with extra form data.

. . .

6 comments

Android: Get an image from device - Mobikul Aug 19, 2016 at 2:42 pm

[…] And you have the image you wanted. You can load this image by converting it in a Bitmap or anything you want to do with it. For uploading this file to server you can follow this link. […]

Sarith Nob Aug 9, 2017 at 9:49 am

Thank you very much!

The code work for me but the file uploaded/file received in server contain only “my_reference_text” not content of my pdf file! Please help me with the issue!

aastha gupta Aug 29, 2017 at 6:49 am
Check the URI you are sending or give me some snippets of your code so I can check what’s wrong.

Reply

Sarith Nob Aug 11, 2017 at 7:15 am

What does function getDataFromInputStream(String, String) (in line 74) do? And how does it do?

aastha gupta Aug 29, 2017 at 6:50 am
Its a custom function I made to parse the result and get the value of a particular key. Its of not use as after you got result you can perform action specific to your need.

Reply

Rizwan Dec 25, 2019 at 4:54 am

Thanks, It helped me!

File upload from Android (via Multipart Form data)

Leave a Comment Cancel Reply

6 comments

Message Sent!