import java.io.File;
import java.io.IOException;
import java.util.List;

public class Main {
    public static void main(String args[]) {
        String charset = "UTF-8";
        File uploadFile1 = new File("E:/123.jpg");

        String requestURL = "https://p...content-available-to-author-only...k.com...";

        try {
            MultipartUtility multipart = new MultipartUtility(requestURL, charset);

            multipart.addHeaderField("User-Agent", "CodeJava");

            multipart.addFilePart("file", uploadFile1);

            List<String> response = multipart.finish();

            for (String line : response) {
                System.out.println(line);
            }
        } catch (IOException ex) {
            System.err.println(ex);
        }

    }
}