Basic Sockets - TCP/IP Sockets in Java Practical Guide for Programmers - page 10

4

public static void main(String[] args) {

5
6

// Get name and IP address of the local host

7

try {

8

InetAddress address = InetAddress.getLocalHost();

9

System.out.println("Local Host:");

10

System.out.println("\t" + address.getHostName());

11

System.out.println("\t" + address.getHostAddress());

12 } catch (UnknownHostException e) {

13 System.out.println("Unable to determine this host's address");

14 }

15
16 for(inti=0;i<args.length; i++) {

17 // Get name(s)/address(es) of hosts given on command line

18 try {

19 InetAddress[] addressList = InetAddress.getAllByName(args[i]);

20

System.out.println(args[i] + ":");

21

// Print the first name. Assume array contains at least one entry.

22

System.out.println("\t" + addressList[0].getHostName());

23

for(intj=0;j<addressList.length; j++)

24

System.out.println("\t" + addressList[j].getHostAddress());

25

} catch (UnknownHostException e) {

26

System.out.println("Unable to find address for " + args[i]);

27

}

28

}

29

}

30 }

InetAddressExample.java

1. Print information about the local host: lines 6-14
Create an InetAddress instance for the local host: line 8
Print the local host information: lines 9-11
getHostName() and getHostAddress() return a string for the host name and IP address,
respectively.

2. Request information for each host specified on the command line: lines 16-28
Create an array of InetAddress instances for the specified host: line 19
InetAddress.getAllByName() returns an array of InetAddress instances, one for each
of the specified host's addresses.
Print the host information: lines 22-24

To use this application to find information about the local host and the publisher's Web server
( www.mkp.com ), do the following: