Getting 500 Error while calling webservice from google app engine - web-services

Question

I am trying to get the response from webservice- http://services.groupkt.com/state/get/IND/all .It is working fine normally through java code but when I have deployed in google app engine it is returning 500 error.
Following one is the code.
try {
// create HTTP Client
HttpClient httpClient = HttpClientBuilder.create().build();
// Create new getRequest with below mentioned URL
HttpGet getRequest = new HttpGet("http://services.groupkt.com/state/get/IND/all");
// Add additional header to getRequest which accepts application/xml data
getRequest.addHeader("accept", "application/json");
// Execute your request and catch response
HttpResponse response = httpClient.execute(getRequest);
// Check for HTTP response code: 200 = success
if (response.getStatusLine().getStatusCode() != 200) {
throw new RuntimeException("Failed : HTTP error code : " + response.getStatusLine().getStatusCode());
}
// Get-Capture Complete application/xml body response
BufferedReader br = new BufferedReader(new InputStreamReader((response.getEntity().getContent())));
String output;
System.out.println("============Output:============");
// Simply iterate through XML response and show on console.
while ((output = br.readLine()) != null) {
System.out.println(output);
}
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
I have searched it.It is showing as internal server error.How can i fix it?