B4J Question doGet Error

public String doGet(String url, String deviceId, String tokena) {
            HttpGet get =null;
            get = new HttpGet(url+"/"+deviceId);
            get.addHeader("app_key", "f8fc0c83-eebd-4926-9ac7-2584831ce303");
            get.addHeader("Authorization","Bearer" + " " + tokena);
            get.setHeader("Content-Type", "Content-Type:application/json; charset=UTF-8");
            try {
               
                HttpResponse response = this.execute(get);
               
                StatusLine statusLine = response.getStatusLine();
             
                int code = statusLine.getStatusCode();

                if(code==HttpURLConnection.HTTP_OK){
                   
                    HttpEntity entity = response.getEntity();
                   
                    InputStream is = entity.getContent();

                    BufferedReader br = new BufferedReader(new InputStreamReader(is));
                    String line = br.readLine();
                    while(line != null){
                        System.out.println(line);
                        line=br.readLine();
                    }
                }
            } catch (ClientProtocolException e1) {
                // TODO Auto-generated catch block
                e1.printStackTrace();
            } catch (IOException e1) {
                // TODO Auto-generated catch block
                e1.printStackTrace();
            }

            return line;
       
}