How to do an HTTPS POST from Android?

I want to do a HTTPS post method to send some data from my android app to my website.

I used HttpURLConnection first and it's working fine with my HTTP URL. My production website is on HTTPS and I want to send the same POST using HttpsURLConnection. Can someone help me use the class properly?

I found some source at this link:

KeyStore keyStore = ...;    
TrustManagerFactory tmf = TrustManagerFactory.getInstance("X509");    
tmf.init(keyStore);

SSLContext context = SSLContext.getInstance("TLS");   
context.init(null, tmf.getTrustManagers(), null);

URL url = new URL("https://www.example.com/");   
HttpsURLConnection urlConnection = (HttpsURLConnection)
url.openConnection();   
urlConnection.setSSLSocketFactory(context.getSocketFactory());   
InputStream in = urlConnection.getInputStream();

What should be the value of KeyStore keyStore = ...;?

I tried sending the data using the same HttpURLConnection, but I am seeing some POST data is missed or in error.

I've tried the method from this question. I am pasting my code below

String urlParameters="dateTime=" + URLEncoder.encode(dateTime,"UTF-8")+
    "&mobileNum="+URLEncoder.encode(mobileNum,"UTF-8");

URL url = new URL(myurl);
HttpsURLConnection conn;
conn=(HttpsURLConnection)url.openConnection();

// Create the SSL connection
SSLContext sc;
sc = SSLContext.getInstance("TLS");
sc.init(null, null, new java.security.SecureRandom());
conn.setSSLSocketFactory(sc.getSocketFactory());
conn.setConnectTimeout(HTTP_CONNECT_TIME_OUT);
conn.setReadTimeout(HTTP_READ_TIME_OUT);

//set the output to true, indicating you are outputting(uploading) POS