Reports instantiations of java.util.Set and java.util.Map that contain java.net.URL objects.

Adding URL objects to such collections can cause performance problems because of calls to the equals() and hashCode() methods of URL.

URL's equals() and hashCode() methods use a DNS lookup, which depending on the availability of the network and the speed of the DNS server can cause significant delays.

Example:


  Set<URL> set = new HashSet<URL>();