Finding IP address of a URL in Java

Prerequisite: InetAddress
getByName() : Returns the InetAddress of the given host. If the host is a literal IP address, then only its validity is checked. Fetches public IP Address of the host specified. It takes the host as an argument and returns the corresponding IP address.

Examples:

Input : www.google.com
Output : 216.58.199.164

Input : localhost
Output : 127.0.0.1

Below programs illustrate how to fetch public IP addresses:

Note: These programs won’t run on online compilers. Use offline compilers like Netbeans, Eclipse, etc, instead.

Program 1: Fetch IP address of any URL 

Java

// Java program to demonstrate
// how to fetch public IP Address
import java.net.*;
import java.*;

class GFG {
    public static void main(String args[])
        throws UnknownHostException
    {
        // The URL for which IP address needs to be fetched
        String s = "https://www.google.com/";

        try {
            // Fetch IP address by getByName()
            InetAddress ip = InetAddress.getByName(new URL(s)
                                                       .getHost());

            // Print the IP address
            System.out.println("Public IP Address of: " + ip);
        }
        catch (MalformedURLException e) {
            // It means the URL is invalid
            System.out.println("Invalid URL");
        }
    }
}

Output:

Public IP Address of: www.google.com/216.58.196.164

Program 2: Fetch the public IP address of one’s system
To find public IP, use http://bot.whatismyipaddress.com. It is an online utility, to find the system’s public IP. Open the URL, read a line and print the line. 

Java

// Java program to demonstrate
// how to fetch public IP Address
import java.net.*;
import java.*;

class GFG {
    public static void main(String args[])
        throws UnknownHostException
    {
        String systemipaddress = "";
        try {
            URL url_name = new URL("http://bot.whatismyipaddress.com");

            BufferedReader sc = new BufferedReader(
                new InputStreamReader(url_name.openStream()));

            // reads system IPAddress
            systemipaddress = sc.readLine().trim();
        }
        catch (Exception e) {
            systemipaddress = "Cannot Execute Properly";
        }
        // Print IP address
        System.out.println("Public IP Address: "
                           + systemipaddress + "\n");
    }
}

Output:

Public IP Address: 103.62.239.242