SOLVED - I solved it by copying my cacerts file from my windows machine to the pi.
I'm writing an application to get a json string from a webserver using long polling, The application ran fine on my windows machine where I was developing. I then moved the source to a raspberry pi and compiled it and now it is throwing this exception:
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 sun.security.ssl.Alerts.getSSLException(Alerts.java:192)
at sun.security.ssl.SSLSocketImpl.fatal(SSLSocketImpl.java:1917)
at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:301)
at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:295)
at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1369)
at sun.security.ssl.ClientHandshaker.processMessage(ClientHandshaker.java:156)
at sun.security.ssl.Handshaker.processLoop(Handshaker.java:925)
at sun.security.ssl.Handshaker.process_record(Handshaker.java:860)
at sun.security.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:1043)
at sun.security.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1343)
at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1371)
at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1355)
at sun.net.www.protocol.https.HttpsClient.afterConnect(HttpsClient.java:563)
at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(AbstractDelegateHttpsURLConnection.java:185)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1511)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1439)
at sun.net.www.protocol.https.HttpsURLConnectionImpl.getInputStream(HttpsURLConnectionImpl.java:254)
at VideoBoard.main(VideoBoard.java:29)
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:387)
at sun.security.validator.PKIXValidator.engineValidate(PKIXValidator.java:292)
at sun.security.validator.Validator.validate(Validator.java:260)
at sun.security.ssl.X509TrustManagerImpl.validate(X509TrustManagerImpl.java:324)
at sun.security.ssl.X509TrustManagerImpl.checkTrusted(X509TrustManagerImpl.java:229)
at sun.security.ssl.X509TrustManagerImpl.checkServerTrusted(X509TrustManagerImpl.java:124)
at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1351)
... 13 more
Caused by: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
at sun.security.provider.certpath.SunCertPathBuilder.build(SunCertPathBuilder.java:145)
at sun.security.provider.certpath.SunCertPathBuilder.engineBuild(SunCertPathBuilder.java:131)
at java.security.cert.CertPathBuilder.build(CertPathBuilder.java:280)
at sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:382)
... 19 more
My website is hosted by GoDaddy and they also are supplying the SSL certificate. There are no issues when accessing the site from my desktop through the browser or java and all indications show that the SSL certificate is valid and trusted by my machine.
The OS you're using on the Raspberry Pi doesn't have a trusted certificate in the certificate path of the one you're using on your server. In other words, the Pi doesn't know to trust that your server is what it says it is.
To fix this, you need to install GoDaddy's root certificate on your Pi. If you're using Raspbian or another Debian-derived OS, here is a good write up on how to do this, and here is GoDaddy's certificate repository.