...
PKIX path building error:
IF there is a PKIX path building failed: SunCertPathBuilderException then most likely the web services security certificate has not been added to Java's cacerts file (file of trusted websites).
The solution is described in the below website.http://magicmonster.com/kb/prg/java/ssl/pkix_path_building_failed.html
This error seems to come about because of an invalid SSL certificate, if the hostname has a valid certificate signed by a CA then this shouldn't be an issue.
4. Create a main method
/**
* Simple sample of main method, it queries the web service for the closest observed holiday to January 1st, 2012.
*/
public static void main(String[] args) throws MalformedURLException
{
...