- Given hostname in java, we would like to find out network details of host.
- JDK class InetAddress provide APIs to fetch network details of hosts.
- We will retrieve network details for:
- Loopback address or localhost
- Get network details for public hosts like facebook or youtube.
- Also, get network details of host if it is mapped to multiple IP addresses.
Get Network details like IPAddress, hostname for loopback:
Example 1: Input loopback hostname i.e. localhost
We will use API InetAddress.getLoopbackAddress() to get loopback details.
Output: We would get network details like IP Address, hostname as follows
Ip Address:127.0.0.1, Host Name: localhost, Canonical Name: 127.0.0.1
Example 2: Get network details for localhost
We will use InetAddress.getLocalHost() to get details like IP address, canonical name.
Output for localhost is: Ip Address:192.168.43.201, Host Name: 5AYX2L07
Get network details for public hosts like facebook or youtube:
Example 3:
Get network details for public hosts like facebook or youtube.
We will use API InetAddress.getByName("www.facebook.com") to fetch network details.
Output: currently, we are getting following details (it may vary)
Ip Address:157.240.7.35, Host Name: www.facebook.com,
Canonical Name: edge-star-mini-shv-01-sin6.facebook.com
Example 4:
Get all network addresses if hostname is mapped to multiple IP address.
Retrieve all network Address of hostname using API InetAddress.getAllByName("www.fb.com")
Output: we are getting output as follows:
Ip Address:31.13.78.35, Host Name: www.fb.com
Network details for hosts (loopback, local & standard hosts) in java
package org.learn.nw;
import java.net.InetAddress;
import java.net.UnknownHostException;
public class HostNameIpAddress {
public static void main(String[] args) throws UnknownHostException {
//Loop back address and hostname
InetAddress inetAddress = InetAddress.getLoopbackAddress();
System.out.println("1. Loop back ip address and hostname");
display(inetAddress);
//Local ip address and hostname
System.out.println("\n2. Local ip address and hostname");
inetAddress = InetAddress.getLocalHost();
display(inetAddress);
//Get IP address of given hostname
System.out.println("\n3. Standard host ip address from hostname");
inetAddress = InetAddress.getByName("www.facebook.com");
display(inetAddress);
//Get list of IP address for given hostname.
System.out.println("\n4. All IP address corresponding to given hostname");
InetAddress[] allInetAddress = InetAddress.getAllByName("www.fb.com");
for(InetAddress netAddress : allInetAddress) {
display(netAddress);
System.out.println();
}
}
private static void display(InetAddress inetAddress) {
System.out.printf("Ip Address:%s, Host Name: %s, Canonical Name: %s",
inetAddress.getHostAddress(), inetAddress.getHostName(),
inetAddress.getCanonicalHostName());
}
}
Output: Network details for hosts in java (example)
1. Loop back ip address and hostname
Ip Address:127.0.0.1, Host Name: localhost, Canonical Name: 127.0.0.1
2. Local ip address and hostname
Ip Address:192.168.43.201, Host Name: 5AYX2L07, Canonical Name: 2YR1L72.xyz.com
3. Standard host ip address from hostname
Ip Address:157.240.7.35, Host Name: www.facebook.com, Canonical Name: edge-star-mini-shv-01-sin6.facebook.com
4. All IP address corresponding to given hostname
Ip Address:31.13.78.35, Host Name: www.fb.com, Canonical Name: edge-star-mini-shv-01-sit4.facebook.com
