InetAddress getCanonicalHostName() in Java

getCanonicalHostName(): This method is available in the java.net.InetAddress class of Java.

Syntax:

String java.net.InetAddress.getCanonicalHostName()

This method gets the fully qualified domain name for this IP address.Best effort method, meaning we may not be able to return the FQDN depending on the underlying system configuration.

Parameters: NA

Returns: the fully qualified domain name for this IP address,or if the operation is not allowed by the security check,the textual representation of the IP address.

Exceptions: NA

Approach

Java

package com.InetAddress;

import java.net.InetAddress;
import java.net.UnknownHostException;

public class InetAddressgetCanonicalHostName {
    public static void main(String[] args) throws UnknownHostException {

        byte addr[] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 1, 2, 3, 4, 5, 6, 7 };
        InetAddress inetAddress = InetAddress.getByAddress(addr);

        System.out.println(inetAddress.getCanonicalHostName());
    }
}

Output:

102:304:506:708:901:203:405:607

Some other methods of InetAddress class

equals(Object): This method compares this object against the specified object.

getAddress(): This method returns the raw IP address of this InetAddress object.

InetAddress.getAllByName(String host): This method returns an array of its IP addresses, based on the configured name service on the system.

InetAddress.getByAddress(byte[]): This method returns an InetAddress object given the raw IP address.

InetAddress.getByAddress(String, byte[]): This method creates an InetAddress based on the provided hostname and IP address.

InetAddress.getByName(String): This method determines the IP address of a host, given the host's name.

getCanonicalHostName(): This method gets the fully qualified domain name for this IP address.

getHostAddress(): This method returns the IP address string in textual presentation.

getHostName(): This method gets the hostname for this IP address.

InetAddress.getLocalHost(): This method returns the address of the local host. 

InetAddress.getLoopbackAddress(): This method returns the loopback address.

hashCode(): This method returns a hashcode for this IP address.

isAnyLocalAddress(): Utility routine to check if the InetAddress is a wildcard address.

isLinkLocalAddress(): Utility routine to check if the InetAddress is a link-local address.

isLoopbackAddress(): Utility routine to check if the InetAddress is a loopback address.

isMCGlobal(): Utility routine to check if the multicast address has global scope.

isMCLinkLocal(): Utility routine to check if the multicast address has link scope.

isMCNodeLocal(): Utility routine to check if the multicast address has node scope.

isMCOrgLocal(): Utility routine to check if the multicast address has organization scope.

isMCSiteLocal(): Utility routine to check if the multicast address has site scope.

isMulticastAddress(): Utility routine to check if the InetAddress is an IP multicast address.

isReachable(int): This method tests whether that address is reachable.

isReachable(NetworkInterface, int, int): This method tests whether that address is reachable.

isSiteLocalAddress(): Utility routine to check if the InetAddress is a site-local address.

toString(): This method converts this IP address to a String.