Java Program to Determine Hostname from IP Address Last Updated : 09 Nov, 2020 Summarize Comments Improve Suggest changes Share Like Article Like Report IP Address stands for internet protocol address. It is an identifying number that is associated with a specific computer or computer network. IP addresses are usually written and displayed in human-readable notation such as 192.168.1.35 in IPv4(32-bit IP address). When connected to the internet, the IP address allows the computers to send and receive information. Every site has its own host link to their own IP Address which helps to send the request by the user to the HTTP traffic and helps to collect the information which the users want This is how an IP address is necessary for every host. There are many ways to get the IP Address of a particular host. So the method which helps to get the IP address for any Host is getHostAddress() of InetAddress class. Syntax: public String getHostAddress() Returns: It returns the raw IP address in a string format.Note: It is easy to find the IP Address from a Hostname. But due to security reasons, it is difficult to get the Host Name from the IP address because all IP addresses are secured. The following methods are used to get the Host Name. getHostName(): This function retrieves the standard hostname for the local computer.getHostByName(): This function retrieves host information corresponding to a hostname from a host database. Example: Obtaining the IP address from the given host Java // Java program to obtain IP Address // from a given host import java.io.*; import java.util.*; import java.net.*; class GFG { public static void main(String[] args) { // Host String host = "www.geeksforgeeks.org"; // Using try Logic So that if there is an error then // easily get the error try { // calling the function which gives the IP // Address from the given host InetAddress[] iaddress = InetAddress.getAllByName(host); for (InetAddress ipaddresses : iaddress) { System.out.println(ipaddresses.toString()); } } catch (UnknownHostException e) { System.out.println(e); } } } Example: Obtaining the Hostname from the Given IP address. All the Server and IP are Secured for a security reason So Hostname directly from the IP address cannot be found. But the Method is similar to found any Hostname from the unsecured IP address. Java // Java program to get Host name // from an ipaddress import java.io.*; import java.net.*; class GFG { public static void main(String[] args) { try { // IP Address InetAddress addr = InetAddress.getByName("23.229.203.68"); // Host name System.out.println("Host name is: " + addr.getHostName()); // Host Address System.out.println("Ip address is: " + addr.getHostAddress()); } catch (UnknownHostException e) { System.out.println(e); } } } OutputHost name is: 23.229.203.68 Ip address is: 23.229.203.68 Comment More infoAdvertise with us Next Article Finding IP address of a URL in Java R rohit2sahu Follow Improve Article Tags : Java Technical Scripter Technical Scripter 2020 Practice Tags : Java Similar Reads Determining the IP Address & Hostname of Local Computer in Java IP Address Stands for Internet Protocol Address, is a numeric label that is assigned uniquely to each device connected within a computer network that uses the internet protocol. 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