, если вы действительно используете http://example.com/, потому что ответ нулевой.
обновление 1
попробуйте этот код:
public static String readUrl(String url, ArrayList<NameValuePair> params, Context context) {
HttpClient client = null;
HttpPost method = null;
InputStream inputStream = null;
String result = null;
HttpResponse response = null;
try {
final HttpParams httpParams = new BasicHttpParams();
HttpConnectionParams.setConnectionTimeout(httpParams,
context.getResources().getInteger(R.integer.serverConnectionTimeout));
HttpConnectionParams.setSoTimeout(httpParams,
context.getResources().getInteger(R.integer.serverConnectionTimeout));
client = new DefaultHttpClient(httpParams);
method = new HttpPost(url);
if (params != null) {
method.setEntity(new UrlEncodedFormEntity(params));
}
response = client.execute(method);
inputStream = response.getEntity().getContent();
result = convertInputStreamToString(inputStream);
} catch (ClientProtocolException ex) {
Log.e("ClientProtocolException", "" + ex.getMessage());
ex.printStackTrace();
} catch (IOException ex) {
Log.e("IOException", "" + ex.getMessage());
} finally {
try {
if (client != null) {
client.getConnectionManager().closeExpiredConnections();
}
} catch (Exception e) {
Log.e("IOException2", "" + e.getMessage());
}
}
return result;
}
private static String convertInputStreamToString(InputStream inputStream) {
try {
BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
StringBuilder builder = new StringBuilder();
String line;
while ((line = reader.readLine()) != null) {
builder.append(line);
}
return builder.toString();
} catch (IOException ex) {
Log.e("InputStreamToString", "" + ex.getMessage());
}
return null;
}