code: private static boolean isBundledInJre(String className) {
      if (className.startsWith("javax.accessibility.")
          || className.startsWith("javax.activation.")
          || className.startsWith("javax.activity.")
          || className.startsWith("javax.annotation.")
          || className.startsWith("javax.crypto.")
          || className.startsWith("javax.imageio.")
          || className.startsWith("javax.jws.")
          || className.startsWith("javax.lang.model.")
          || className.startsWith("javax.management.")
          || className.startsWith("javax.naming.")
          || className.startsWith("javax.net.")
          || className.startsWith("javax.print.")
          || className.startsWith("javax.rmi.")
          || className.startsWith("javax.script.")
          || className.startsWith("javax.security.")
          || className.startsWith("javax.sound.")
          || className.startsWith("javax.sql.")
          || className.startsWith("javax.swing.")
          || className.startsWith("javax.tools.")
          || className.startsWith("javax.transaction.")
          || className.startsWith("javax.xml.")) {
        return true;
      }
      return false;
    }
docs: javax packages are tricky. Some are in the JRE. Some aren't.