Certificate added to keystore still getting Exception !

[Anand Athinarayanan]

Hello Ranchers,
This is my first post here and I hope i'm posting it in the correct forum, if not please forgive. Ok so here is my problem.
I have a stand alone java class (with main method) which connects to a secure webservice. I have generated the client stubs and imported it in my client code(the java class) .
Since the webservice is secure I have added the certificate that i was provided with, to my keystore using the keytool command.
I even got a message "certificate successfully added to the keystore".
I have set the path to the keystore in my System properties in my code.
But when I execute my java program I get the following error

"unable to find valid certification path to requested target". And more exceptions like this

javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
	at com.sun.net.ssl.internal.ssl.Alerts.getSSLException(Alerts.java:150)
	at com.sun.net.ssl.internal.ssl.SSLSocketImpl.fatal(SSLSocketImpl.java:1476)
	at com.sun.net.ssl.internal.ssl.Handshaker.fatalSE(Handshaker.java:174)
	at com.sun.net.ssl.internal.ssl.Handshaker.fatalSE(Handshaker.java:168)
	at com.sun.net.ssl.internal.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:846)
	at com.sun.net.ssl.internal.ssl.ClientHandshaker.processMessage(ClientHandshaker.java:106)
	at com.sun.net.ssl.internal.ssl.Handshaker.processLoop(Handshaker.java:495)
	at com.sun.net.ssl.internal.ssl.Handshaker.process_record(Handshaker.java:433)
	at com.sun.net.ssl.internal.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:815)
	at com.sun.net.ssl.internal.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1025)
	at com.sun.net.ssl.internal.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1038)
	at InstallCert.main(InstallCert.java:63)
Caused by: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
	at sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:221)
	at sun.security.validator.PKIXValidator.engineValidate(PKIXValidator.java:145)
	at sun.security.validator.Validator.validate(Validator.java:203)
	at com.sun.net.ssl.internal.ssl.X509TrustManagerImpl.checkServerTrusted(X509TrustManagerImpl.java:172)
	at InstallCert$SavingTrustManager.checkServerTrusted(InstallCert.java:158)
	at com.sun.net.ssl.internal.ssl.JsseX509TrustManager.checkServerTrusted(SSLContextImpl.java:320)
	at com.sun.net.ssl.internal.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:839)
	... 7 more

Is there anything else I need to do or what am I doing wrong here?