com.google.gcloud.datastore.DatastoreException: I/O error
    at com.google.gcloud.spi.DefaultDatastoreRpc.translate(DefaultDatastoreRpc.java:110)
    at com.google.gcloud.spi.DefaultDatastoreRpc.lookup(DefaultDatastoreRpc.java:147)
    at com.google.gcloud.datastore.DatastoreOptions.normalize(DatastoreOptions.java:128)
    at com.google.gcloud.datastore.DatastoreOptions.access$400(DatastoreOptions.java:36)
    at com.google.gcloud.datastore.DatastoreOptions$Builder.build(DatastoreOptions.java:89)
    at com.google.gcloud.datastore.DatastoreOptions.defaultInstance(DatastoreOptions.java:175)
    at com.industryopenings.seeker.driver.Driver.main(Driver.java:97)
Caused by: com.google.api.services.datastore.client.DatastoreException: I/O error
    at com.google.api.services.datastore.client.RemoteRpc.makeException(RemoteRpc.java:115)
    at com.google.api.services.datastore.client.RemoteRpc.call(RemoteRpc.java:83)
    at com.google.api.services.datastore.client.BaseDatastoreFactory$RemoteRpc.call(BaseDatastoreFactory.java:41)
    at com.google.api.services.datastore.client.Datastore.lookup(Datastore.java:93)
    at com.google.gcloud.spi.DefaultDatastoreRpc.lookup(DefaultDatastoreRpc.java:145)
    ... 5 more
Caused by: 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(Unknown Source)
    at sun.security.ssl.SSLSocketImpl.fatal(Unknown Source)
    at sun.security.ssl.Handshaker.fatalSE(Unknown Source)
    at sun.security.ssl.Handshaker.fatalSE(Unknown Source)
    at sun.security.ssl.ClientHandshaker.serverCertificate(Unknown Source)
    at sun.security.ssl.ClientHandshaker.processMessage(Unknown Source)
    at sun.security.ssl.Handshaker.processLoop(Unknown Source)
    at sun.security.ssl.Handshaker.process_record(Unknown Source)
    at sun.security.ssl.SSLSocketImpl.readRecord(Unknown Source)
    at sun.security.ssl.SSLSocketImpl.performInitialHandshake(Unknown Source)
    at sun.security.ssl.SSLSocketImpl.startHandshake(Unknown Source)
    at sun.security.ssl.SSLSocketImpl.startHandshake(Unknown Source)
    at sun.net.www.protocol.https.HttpsClient.afterConnect(Unknown Source)
    at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(Unknown Source)
    at sun.net.www.protocol.http.HttpURLConnection.getOutputStream0(Unknown Source)
    at sun.net.www.protocol.http.HttpURLConnection.getOutputStream(Unknown Source)
    at sun.net.www.protocol.https.HttpsURLConnectionImpl.getOutputStream(Unknown Source)
    at com.google.api.client.http.javanet.NetHttpRequest.execute(NetHttpRequest.java:77)
    at com.google.api.client.http.HttpRequest.execute(HttpRequest.java:972)
    at com.google.auth.oauth2.UserCredentials.refreshAccessToken(UserCredentials.java:121)
    at com.google.auth.oauth2.OAuth2Credentials.refresh(OAuth2Credentials.java:97)
    at com.google.auth.oauth2.OAuth2Credentials.getRequestMetadata(OAuth2Credentials.java:74)
    at com.google.auth.http.HttpCredentialsAdapter.initialize(HttpCredentialsAdapter.java:65)
    at com.google.gcloud.ServiceOptions$1.initialize(ServiceOptions.java:533)
    at com.google.api.services.datastore.client.RemoteRpc.call(RemoteRpc.java:76)
    ... 8 more
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(Unknown Source)
    at sun.security.validator.PKIXValidator.engineValidate(Unknown Source)
    at sun.security.validator.Validator.validate(Unknown Source)
    at sun.security.ssl.X509TrustManagerImpl.validate(Unknown Source)
    at sun.security.ssl.X509TrustManagerImpl.checkTrusted(Unknown Source)
    at sun.security.ssl.X509TrustManagerImpl.checkServerTrusted(Unknown Source)
    ... 29 more
Caused by: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
    at sun.security.provider.certpath.SunCertPathBuilder.build(Unknown Source)
    at sun.security.provider.certpath.SunCertPathBuilder.engineBuild(Unknown Source)
    at java.security.cert.CertPathBuilder.build(Unknown Source)
    ... 35 more