InetAddress Example Program in Java

The inetaddress class has no visible constructors. To create a inetaddress object, you had to use one of the available factory methods. Factory Methods is merely a convention whereby static methods in a class return an instance of the that class. This was done in lieu of overloading a constructor with various parameter lists when have unique method names makes the R Esults much clearer. In the case of InetAddress, the three methods Getlocalhost (), getbyname (), and Getallbynam E () can is used to create instances of inetaddress. These methods is shown here:

 static   inetaddress Getlocalhost ()  throws   Unknownhostexception  static   InetAddress Getbyname (String hostName)  throws   Unknownhostexception  static   inetaddress[] Getallbyname (String hostName)  throws  Unknownhostexception 

The getlocalhost () method simply returns the inetaddress object that represents the local host. The getbyname () method returns an inetaddress for a host name passed to it. If These methods is unable to resolve the host name, they throw an unknownhostexception.

On the Internet, it's common for A and a single name to being used to represent several machines. In the world of Web servers, this is one-to-provide some degree of scaling. The getallbyname () factory method returns an array of inetaddresses, represent all of the addresses That a particular the name resolves to. It would also throw an unknownhostexception if it can ' t resolve the name to at least one address.

The following example prints the addresses and names of the local machine and both well-known Internet Web sites:

 Packageorg.javalobby.tnt.net;//demonstrate inetaddress.Importjava.net.*; Public classInetaddresstest { Public Static voidMain (String args[])throwsunknownhostexception {inetaddress Address=Inetaddress.getlocalhost ();        System.out.println (Address); Address= Inetaddress.getbyname ("starwave.com");        System.out.println (Address); InetAddress sw[]= Inetaddress.getallbyname ("www.baidu.com");  for(inti = 0; i < sw.length; i++) System.out.println (Sw[i]); Address= Inetaddress.getbyname ("www.xxdhngx.com"); }}

Here are the output produced by this program. (Of course, the output you see would be slightly different.)

default/206.148.209.138starwave.com/199.181.132.250www.baidu.com/180.97.33.108www.baidu.com/180.97.33.107www.baidu.com/61.135.169.125www.baidu.com/61.135.169.121Exception in Thread"Main"java.net.UnknownHostException:www.xxdhngx.com at Java.net.Inet6AddressImpl.lookupAllHostAddr (Native Method) at java.net.inetaddress$1.LOOKUPALLHOSTADDR (inetaddress.java:901) at Java.net.InetAddress.getAddressesFromNameService (Inetaddress.java:1293) at JAVA.NET.INETADDRESS.GETALLBYNAME0 (Inetaddress.java:1246) at Java.net.InetAddress.getAllByName (Inetaddress.java:1162) at Java.net.InetAddress.getAllByName (Inetaddress.java:1098) at Java.net.InetAddress.getByName (Inetaddress.java:1048) at Org.javalobby.tnt.net.InetAddressTest.main (Inetaddresstest.java:15)

This tutorial is a extract from the "The Complete Reference Part 2 by Herbert Schildt".

InetAddress Example Program in Java