Answer by Cedric Simon for Resolving javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed Error?

Using Tomcat 7 under Linux, this did the trick.

String certificatesTrustStorePath = "/etc/alternatives/jre/lib/security/cacerts";System.setProperty("javax.net.ssl.trustStore", certificatesTrustStorePath);System.setProperty("javax.net.ssl.trustStorePassword", "changeit");

Under Linux, $JAVA_HOME is not always setup, but usually /etc/alternatives/jre points to $JAVA_HOME/jre