how to use okhttp to upload a file?

I've created cool helper class for OkHttp3. it here

public class OkHttp3Helper {

    public static final String TAG;
    private static final okhttp3.OkHttpClient client;

    static {
        TAG = OkHttp3Helper.class.getSimpleName();
        client = new okhttp3.OkHttpClient.Builder()
                .readTimeout(7, TimeUnit.MINUTES)
                .writeTimeout(7, TimeUnit.MINUTES)
                .build();
    }

    private Context context;

    public OkHttp3Helper(Context context) {
        this.context = context;
    }

    /**
     * <strong>Uses:</strong><br/>
     * <p>
     * {@code
     * ArrayMap<String, String> formField = new ArrayMap<>();}
     * <br/>
     * {@code formField.put("key1", "value1");}<br/>
     * {@code formField.put("key2", "value2");}<br/>
     * {@code formField.put("key3", "value3");}<br/>
     * <br/>
     * {@code String response = helper.postToServer("http://www.example.com/", formField);}<br/>
     * </p>
     *
     * @param url       String
     * @param formField android.support.v4.util.ArrayMap
     * @return response from server in String format
     * @throws Exception
     */
    @NonNull
    public String postToServer(@NonNull String url, @Nullable ArrayMap<String, String> formField)
            throws Exception {
        okhttp3.Request.Builder requestBuilder = new okhttp3.Request.Builder().url(url);
        if (formField != null) {
            okhttp3.FormBody.Builder formBodyBuilder = new okhttp3.FormBody.Builder();
            for (Map.Entry<String, String> entry : formField.entrySet()) {
                formBodyBuilder.add(entry.getKey(), entry.getValue());
            }
            requestBuilder.post(formBodyBuilder.build());
        }
        okhttp3.Request request = requestBuilder.build();
        okhttp3.Response response = client.newCall(request).execute();
        if (!response.isSuccessful()) {
            throw new IOException(response.message());
        }
        return response.body().string();
    }

    /**
     * <strong>Uses:</strong><br/>
     * <p>
     * {@code
     * ArrayMap<String, String> formField = new ArrayMap<>();}
     * <br/>
     * {@code formField.put("key1", "value1");}<br/>
     * {@code formField.put("key2", "value2");}<br/>
     * {@code formField.put("key3", "value3");}<br/>
     * <br/>
     * {@code
     * ArrayMap<String, File> filePart = new ArrayMap<>();}
     * <br/>
     * {@code filePart.put("key1", new File("pathname"));}<br/>
     * {@code filePart.put("key2", new File("pathname"));}<br/>
     * {@code filePart.put("key3", new File("pathname"));}<br/>
     * <br/>
     * {@code String response = helper.postToServer("http://www.example.com/", formField, filePart);}<br/>
     * </p>
     *
     * @param url       String
     * @param formField android.support.v4.util.ArrayMap
     * @param filePart  android.support.v4.util.ArrayMap
     * @return response from server in String format
     * @throws Exception
     */
    @NonNull
    public String postMultiPartToServer(@NonNull String url,
                                        @Nullable ArrayMap<String, String> formField,
                                        @Nullable ArrayMap<String, File> filePart)
            throws Exception {
        okhttp3.Request.Builder requestBuilder = new okhttp3.Request.Builder().url(url);
        if (formField != null || filePart != null) {
            okhttp3.MultipartBody.Builder multipartBodyBuilder = new okhttp3.MultipartBody.Builder();
            multipartBodyBuilder.setType(okhttp3.MultipartBody.FORM);
            if (formField != null) {
                for (Map.Entry<String, String> entry : formField.entrySet()) {
                    multipartBodyBuilder.addFormDataPart(entry.getKey(), entry.getValue());
                }
            }
            if (filePart != null) {
                for (Map.Entry<String, File> entry : filePart.entrySet()) {
                    File file = entry.getValue();
                    multipartBodyBuilder.addFormDataPart(
                            entry.getKey(),
                            file.getName(),
                            okhttp3.RequestBody.create(getMediaType(file.toURI()), file)
                    );
                }
            }
            requestBuilder.post(multipartBodyBuilder.build());
        }
        okhttp3.Request request = requestBuilder.build();
        okhttp3.Response response = client.newCall(request).execute();
        if (!response.isSuccessful()) {
            throw new IOException(response.message());
        }
        return response.body().string();
    }

    private okhttp3.MediaType getMediaType(URI uri1) {
        Uri uri = Uri.parse(uri1.toString());
        String mimeType;
        if (uri.getScheme().equals(ContentResolver.SCHEME_CONTENT)) {
            ContentResolver cr = context.getContentResolver();
            mimeType = cr.getType(uri);
        } else {
            String fileExtension = MimeTypeMap.getFileExtensionFromUrl(uri
                    .toString());
            mimeType = MimeTypeMap.getSingleton().getMimeTypeFromExtension(
                    fileExtension.toLowerCase());
        }
        return okhttp3.MediaType.parse(mimeType);
    }
}

Here's an answer that works with OkHttp 3.2.0:

public void upload(String url, File file) throws IOException {
    OkHttpClient client = new OkHttpClient();
    RequestBody formBody = new MultipartBody.Builder()
        .setType(MultipartBody.FORM)
        .addFormDataPart("file", file.getName(),
            RequestBody.create(MediaType.parse("text/plain"), file))
        .addFormDataPart("other_field", "other_field_value")
        .build();
    Request request = new Request.Builder().url(url).post(formBody).build();
    Response response = client.newCall(request).execute();
}

Here is a basic function that uses okhttp to upload a file and some arbitrary field (it literally simulates a regular HTML form submission)

Change the mime type to match your file (here I am assuming .csv) or make it a parameter to the function if you are going to upload different file types

  public static Boolean uploadFile(String serverURL, File file) {
    try {

        RequestBody requestBody = new MultipartBody.Builder().setType(MultipartBody.FORM)
                .addFormDataPart("file", file.getName(),
                        RequestBody.create(MediaType.parse("text/csv"), file))
                .addFormDataPart("some-field", "some-value")
                .build();

        Request request = new Request.Builder()
                .url(serverURL)
                .post(requestBody)
                .build();

        client.newCall(request).enqueue(new Callback() {

            @Override
            public void onFailure(final Call call, final IOException e) {
                // Handle the error
            }

            @Override
            public void onResponse(final Call call, final Response response) throws IOException {
                if (!response.isSuccessful()) {
                    // Handle the error
                }
                // Upload successful
            }
        });

        return true;
    } catch (Exception ex) {
        // Handle the error
    }
    return false;
}

Note: because it is async call, the boolean return type does not indicate successful upload but only that the request was submitted to okhttp queue.


Note: this answer is for okhttp 1.x/2.x. For 3.x, see this other answer.

The class Multipart from mimecraft encapsulates the whole HTTP body and can handle regular fields like so:

Multipart m = new Multipart.Builder()
        .type(Multipart.Type.FORM)
        .addPart(new Part.Builder()
                .body("value")
                .contentDisposition("form-data; name=\"non_file_field\"")
                .build())
        .addPart(new Part.Builder()
                .contentType("text/csv")
                .body(aFile)
                .contentDisposition("form-data; name=\"file_field\"; filename=\"file1\"")
                .build())
        .build();

Take a look at examples of multipart/form-data encoding to get a sense of how you need to construct the parts.

Once you have a Multipart object, all that's left to do is specify the right Content-Type header and pass on the body bytes to the request.

Since you seem to be working with the v2.0 of the OkHttp API, which I don't have experience with, this is just guess code:

// You'll probably need to change the MediaType to use the Content-Type
// from the multipart object
Request.Body body =  Request.Body.create(
        MediaType.parse(m.getHeaders().get("Content-Type")),
        out.toByteArray());

For OkHttp 1.5.4, here is a stripped down code I'm using which is adapted from a sample snippet:

OkHttpClient client = new OkHttpClient();
OutputStream out = null;
try {
    URL url = new URL("http://www.example.com");
    HttpURLConnection connection = client.open(url);
    for (Map.Entry<String, String> entry : multipart.getHeaders().entrySet()) {
        connection.addRequestProperty(entry.getKey(), entry.getValue());
    }
    connection.setRequestMethod("POST");
    // Write the request.
    out = connection.getOutputStream();
    multipart.writeBodyTo(out);
    out.close();

    // Read the response.
    if (connection.getResponseCode() != HttpURLConnection.HTTP_OK) {
        throw new IOException("Unexpected HTTP response: "
                + connection.getResponseCode() + " " + connection.getResponseMessage());
    }
} finally {
    // Clean up.
    try {
        if (out != null) out.close();
    } catch (Exception e) {
    }
}