public final class NetMask extends Object
 The constructor takes a string as an argument which represents a netmask, as
 per the CIDR notation -- whether this netmask be IPv4 or IPv6. It then
 extracts the network address (before the /) and the CIDR prefix (after the
 /), and tells through the #matches() method whether a candidate
 InetAddress object fits in the recorded range.
 
 As byte arrays as returned by InetAddress.getByName() are always
 in network byte order, finding a match is therefore as simple as testing
 whether the n first bits (where n is the CIDR) are the same in both byte
 arrays (the one of the network address and the one of the candidate address).
 We do that by first doing byte comparisons, then testing the last bits if any
 (that is, if the remainder of the integer division of the CIDR by 8 is not
 0).
 
As a bonus, if no '/' is found in the input, it is assumed that an exact address match is required.
public NetMask(String input)
input - the CIDR netmaskIllegalArgumentException - if the netmask is not correct (invalid
             address specification, malformed CIDR prefix, etc)public boolean matches(InetAddress addr)
addr - The InetAddress to testCopyright © 2000-2020 Apache Software Foundation. All Rights Reserved.