public String performPost(File file, String url) {
    HttpPost httppost = new HttpPost(url);
    InputStream content = null;

    try {

        List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(2);
        nameValuePairs.add(new BasicNameValuePair("articleattachement[content]", encode(file)));

        httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));

        Log.d("DEBUG", "UPLOAD: executing request: " + httppost.getRequestLine());
        Log.d("DEBUG", "UPLOAD: request: " + httppost.getEntity().getContentType().toString());

        content = execute(httppost).getEntity().getContent();

        ByteArrayOutputStream bout = new ByteArrayOutputStream();
        byte[] buf = new byte[1024];
        int len;
        while ((len = content.read(buf)) > 0) {
            bout.write(buf, 0, len);
        }
        content.close();
        return bout.toString();
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (ClientProtocolException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }
    return null;
}

public String encode(File file) throws IOException {
    byte[] data=null;
    try {

        data = getFileBytes(new FileInputStream(file.getAbsolutePath()));
    } catch (Exception e) {
        e.printStackTrace();
    }

    return Base64.encodeToString(data,Base64.URL_SAFE);
}

public byte[] getFileBytes(InputStream ios) throws IOException {
    ByteArrayOutputStream ous = null;
    //InputStream ios = null;
    try {
        byte[] buffer = new byte[4096];
        ous = new ByteArrayOutputStream();
        //ios = new FileInputStream(file);
        int read = 0;
        while ((read = ios.read(buffer)) != -1)
            ous.write(buffer, 0, read);
    } finally {
        try {
            if (ous != null)
                ous.close();
        } catch (IOException e) {
            // swallow, since not that important
        }
        try {
            if (ios != null)
                ios.close();
        } catch (IOException e) {
            // swallow, since not that important
        }
    }
    return ous.toByteArray();
}