Answer by Ashwin S Ashok for How to fix 'android.os.NetworkOnMainThreadException'?

The error is due to executing long running operations in main thread,You can easily rectify the problem by using AsynTask or Thread. You can checkout this library AsyncHTTPClient for better handling.

AsyncHttpClient client = new AsyncHttpClient();
client.get("http://www.google.com", new AsyncHttpResponseHandler() {

    @Override
    public void onStart() {
        // Called before a request is started
    }

    @Override
    public void onSuccess(int statusCode, Header[] headers, byte[] response) {
        // Called when response HTTP status is "200 OK"
    }

    @Override
    public void onFailure(int statusCode, Header[] headers, byte[] errorResponse, Throwable e) {
        // Called when response HTTP status is "4XX" (for example, 401, 403, 404)
    }

    @Override
    public void onRetry(int retryNo) {
        // Called when request is retried
    }
});