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>();