There are a couple of places in the public java.net Content Handler API that incorrectly specify an implementation specific location of handler classes:

1) java.net.URLConnection.getContent() incorrectly specifies the default location of content handler classes as sun.net.www.content. ( this location is implementation specific )
  
    "If no content handler factory has yet been set up, or if the factory's createContentHandler method returns null, then the application loads the class named:
        sun.net.www.content.<contentType> "

2) java.net.ContentHandler also incorrectly makes reference to the implementation specific sun.net.www.content package.