Java Security

I wrote below program to access content of secure site https://solar.mkcl.org. but this is showing me exception
"*javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path validation failed: java.security.cert.CertPathValidatorException: subject/issuer name chaining check failed"*

Code is:
import java.net.URL;
import java.io.*;
import javax.net.ssl.HttpsURLConnection;

public class Test1
{
public static void main(String[] args)
throws Exception
{
String httpsURL = "https://solar.mkcl.org" ;

URL myurl = new URL(httpsURL);
HttpsURLConnection con = (HttpsURLConnection)myurl.openConnection();
InputStream ins = con.getInputStream();
InputStreamReader isr=new InputStreamReader(ins);
BufferedReader in =new BufferedReader(isr);
String inputLine;

while ((inputLine = in.readLine()) != null)
System.out.println(inputLine);

in.close();
}
}

This program is not working for https:solar.mkcl.org & i need to solve this problem
can any one help me?