Interacting with Networks and Databases - Beginning Java 7 - page 790

InetAddress declaresseveralclassmethodsforobtainingan InetAddress in-
stance. These methods include the following:
• InetAddress[] getAllByName(String host) returns an array
of InetAddress es that store the IP addresses associated with host . You
can pass either a domain name (e.g., " tutortutor.ca ") or an IP address
(e.g.," 70.33.247.10 ")argumenttothisparameter.(CheckoutWikipedia's
“Domain name” entry [ http://en.wikipedia.org/wiki/Do-
main_name ] to learn about domain names.) Passing null results in an
InetAddress instance that stores the IP address of the loopback interface
(defined shortly). This method throws
java.net.UnknownHostException when no IP address for the speci-
fied host canbefound,orwhenascopeidentifierisspecifiedforaglobalIPv6
address.
• InetAddress getByAddress(byte[] addr) returns an InetAd-
dress object for the given raw IP address. The argument passed to addr is
in network byte order (mostsignificantbytefirst)wherethehighestorderbyte
is in addr[0] . The length of the addr array must be four bytes long for an
IPv4 address and sixteen bytes long for an IPv6 address. This method throws
UnknownHostException when the array's length is neither 4 nor 16.
• InetAddress getByAddress(String host, byte[] addr) re-
turns an InetAddress instance based on the provided host name and IP
address. This method throws UnknownHostException when the array's
length is neither 4 nor 16.
• InetAddress getByName(String host) is equivalent to specifying
getAllByName(host)[0] .
• InetAddress getLocalHost() returns the address of the local host
(the current host), which is represented by hostname localhost or by an IP
address that is typically 127.0.0.1 [IPv4] or ::1 [IPv6)]. This method throws
UnknownHostException when localhost couldn't be resolved into an ad-
dress.
• InetAddress getLoopbackAddress() returnsthe loopback address (a
specialIPaddressthatallowsnetwork-management softwaretotreatoutgoing
messages as incoming messages). The returned InetAddress instance rep-
resentstheIPv4loopbackaddress,127.0.0.1,ortheIPv6loopbackaddress,::1.
TheIPv4loopbackaddressreturnedisonlyoneofmanyintheform127.*.*.*,
where * is a wildcard that ranges from 0 through 255.