UploadImage.java

import java.io.BufferedReader;
import java.io.File;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLConnection;
import java.nio.file.Files;

public class Main {

  public static void main(String[] args) throws IOException {
    String url = "http://surlfpgu.eu-4.evennode.com/dev/api/client/account/profile/uploadpic";
    String charset = "UTF-8";
    String param = "8f205c6a5712a8b18ae95f0553e7e413f8d5b319fb7343f441cc73617626a5ab";
    File binaryFile = new File("/home/guftall/Pictures/img1.jpg");
    String boundary = Long.toHexString(System.currentTimeMillis()); // Just generate some unique random value.
    String CRLF = "\r\n"; // Line separator required by multipart/form-data.

    URLConnection connection = new URL(url).openConnection();
    connection.setDoOutput(true);
    connection.setRequestProperty("Content-Type", "multipart/form-data; boundary=" + boundary);
    connection.setRequestProperty("ls": param);

try (
        OutputStream output = connection.getOutputStream();
        PrintWriter writer = new PrintWriter(new OutputStreamWriter(output, charset), true);
    ) {
        // Send binary file.
        writer.append("--" + boundary).append(CRLF);
        writer.append("Content-Disposition: form-data; name=\"avatar\"; filename=\"" + binaryFile.getName() + "\"").append(CRLF);
        writer.append("Content-Type: " + URLConnection.guessContentTypeFromName(binaryFile.getName())).append(CRLF);
        writer.append("Content-Transfer-Encoding: binary").append(CRLF);
        writer.append(CRLF).flush();
        Files.copy(binaryFile.toPath(), output);
        output.flush(); // Important before continuing with writer!
        writer.append(CRLF).flush(); // CRLF is important! It indicates end of boundary.

        // End of multipart/form-data.
        writer.append("--" + boundary + "--").append(CRLF).flush();
    }

    // Request is lazily fired whenever you need to obtain information about response.
    int responseCode = ((HttpURLConnection) connection).getResponseCode();
    System.out.println(responseCode); // Should be 200

    BufferedReader bufferedReader = new BufferedReader(
        new InputStreamReader(((HttpURLConnection) connection).getInputStream()));

    StringBuilder sBuilder = new StringBuilder();

    String output;
    while((output = bufferedReader.readLine()) != null) {
      sBuilder.append(output);
    }

    System.out.println(sBuilder.toString());

  }
}