It's easy to say that, but that's not the default in Java and it takes a decent amount of work to completely decouple yourself. For example: it uses XML all over the place to setup and configure things and, by default, will validate these XML files against a schema at a URL. If that URL starts redirecting to a splash page (as http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd currently does), it breaks the build.
