InetAddress.getByName(String) in Java

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

Syntax:

InetAddress java.net.InetAddress.getByName(String host) throws UnknownHostException

This method takes one argument. This method determines the IP address of a host, given the host's name.

The host name can either be a machine name, such as"www.example.com", or a textual representation of itsIP address. If a literal IP address is supplied, only the validity of the address format is checked.

Parameters: One parameter is required for this method.

host: the specified host, or null.

Returns: an IP address for the given host name.

Throws:

1. UnknownHostException - if no IP address for the host could be found, or if a scope_id was specified for a global IPv6 address.

2. SecurityException - if a security manager exist sand its checkConnect method doesn't allow the operation

Approach 1: When no exception

Java

package com.InetAddress;

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

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

        String host = "[beingcodeexpert.blogspot.com]";

        InetAddress inetAddress = InetAddress.getByName(host);

        System.out.println(inetAddress);
    }
}

Output:

beingcodeexpert.blogspot.com/142.250.193.1

Approach 2: UnknownHostException 

Java

package com.InetAddress;

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

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

        String host = "hello";

        InetAddress inetAddress = InetAddress.getByName(host);

        System.out.println(inetAddress);
    }
}

Output:

Exception in thread "main" java.net.UnknownHostException: No such host is known (hello)
	at java.base/java.net.Inet6AddressImpl.lookupAllHostAddr(Native Method)
	at java.base/java.net.InetAddress$PlatformNameService.lookupAllHostAddr(InetAddress.java:932)
	at java.base/java.net.InetAddress.getAddressesFromNameService(InetAddress.java:1517)
	at java.base/java.net.InetAddress$NameServiceAddresses.get(InetAddress.java:851)
	at java.base/java.net.InetAddress.getAllByName0(InetAddress.java:1507)
	at java.base/java.net.InetAddress.getAllByName(InetAddress.java:1366)
	at java.base/java.net.InetAddress.getAllByName(InetAddress.java:1300)
	at java.base/java.net.InetAddress.getByName(InetAddress.java:1250)
	at com.InetAddress.InetAddressgetByName.main(InetAddressgetByName.java:11)

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.