"SSLHandshakeException: Couldn't find trusted certificate" when POSTing

Question

... to a https.
My Java application basically has to send a user name/password to a https login page. This is done through a Login dialog in the application.
I am at the very beginning, where I create an HTTPS connection. This is how the code looks like:
try
URL url = new URL("https://www.sun.com");
HttpsURLConnection conn = (HttpsURLConnection)url.openConnection();
conn.setDoOutput(true); // the default is false
conn.setDoInput(true); // if DoOutput is set to true, the default is false
conn.setRequestMethod("POST"); // Sets the request method to POST, and enable to send data
conn.setUseCaches (false); // No caching, we want the real thing.
// write arguments & Send POST output to the web server
DataOutputStream printout = new DataOutputStream(conn.getOutputStream ());
// ...Print args and GET response data, etc.
conn.disconnect();
catch(IOException ioe)
System.out.println(ioe);
============================================
As soon as I reach the line 'DataOutputStream printout = new DataOutputStream(conn.getOutputStream ());', the above exception is thrown.
What am I doing wrong?!? (If I am using a different https, for testing purposes, https://www.skipjackic.com/secure/echo.asp, I get back the correct response data).
Also, how do I know how to post values to certain fields (I don't know their names, only that they should receive username & password) located in a htm page?
Thank you.

Answer 1

While connecting to sun.com server, ur client program verifies the identity of the server whom it is connecting to(in a SSL connection). So ur java client program needs to send a 'TrustStore' file which wud contain the verification details of the identity of the server certificate. First, U need to download the server certificate & then using the 'keytool' utility, u need to create a TrustStore file(which wud be later passed to ur java client program).