Posts Tagged ‘url’
java.net.URL is based on a fancy rule saying that URLs of two hosts are equal as long as they are resolving to the same IP address. It is known to be incompatible with virtual hosting and should not be used.
URL.equals() would consider the URL of this blog (https://javaantipatterns.wordpress.com) to be equal to an URL of any random blog hosted on WordPress – that is obviously not true.
It is recommended to use java.net.URI objects instead.
java.net.URL class is an absolute champion in a number of implemented antipatterns of
hashCode() as well):
java.net.URL objects used as Map keys or Set items can result in a big performance issue. Internal implementation of
hashCode() methods of java.net.URL class performs domain name resolution, so the time of their execution relies on an internet connection speed. If a computer is off-line, the time is nearly equal to a connection timeout (tens of seconds).
The same problem arises every time when URLs equality checking or hash code computation is performed.
Do not use
java.net.URL to keep URL values. Use
java.net.URI objects or the simple Strings instead.