Sample method for posting a multipart file to rest api with OkHttp

post-file.java

/**********
* Here is a method showing use of OkHttp for posting a multipart form data
*
* Here RPResumeResponseDTO is a custom DTO being used in the project
* For taking file from rest api endpoint we are using as a multipart file parameter
**********/
/**************Steps *******************/

RPResumeResponseDTO postResumeToRPServer(MultipartFile file) throws IOException {
        log.debug("Request to post file : {}",file.getOriginalFilename());
        / * Use your Custom object to handle data if any in place of  */
        RPResumeResponseDTO resumeResponseDTO = new RPResumeResponseDTO();
        
/*** Step 1*********************
** Initialize OkHttp Client****
******************************/
  
        OkHttpClient okHttpClient = new OkHttpClient()
            .newBuilder()
            .connectTimeout(60, TimeUnit.SECONDS)
            .build();

/*******Step 2************************************************************
** Create a Multipart Body to handle data params and file we need to send **
***************************************************************************/
        // A request body to append file
        RequestBody fileBody = RequestBody.create(okhttp3.MediaType.parse(file.getContentType()), file.getBytes());

        MultipartBody multipartBody = new MultipartBody.Builder()
            .setType(MultipartBody.FORM)  // Header to show we are sending a Multipart Form Data
            .addFormDataPart("resumeFile", file.getOriginalFilename(),fileBody) // file param
            .addFormDataPart("someText", "textValue") // other string params can be like userId, name or something
            .build();
  
/*******Step 3************************************************************
** Create Request to call the api passing api url**
***************************************************************************/

        Request request = new Request.Builder()
            .url(apiEndpoint)  // pass the url endpoint of api
            .post(multipartBody) // pass the mulipart object we just created having data
            .build();
  
/*******Step 4************************************************************
** Execute the api and create a Response Object to handle response**
***************************************************************************/
  
        Response resp = okHttpClient.newCall(request).execute();

/*******Step 5************************************************************
** Handling data from Response**
***************************************************************************/
        String response = resp.body().string();
        if(response) {
            /* DO something with your response here or parse response to a object */ 

           // For mapping the response to your custom class
            ObjectMapper objectMapper = new ObjectMapper();
            resumeResponseDTO = objectMapper.readValue(response, RPResumeResponseDTO.class);
        }
        resp.close(); // Close response
        return resumeResponseDTO;
    }

Thank you kindly.