public class NetInfo { public static void main(String[] args) { new NetInfo().say(); } public void say() { try { java.net.InetAddress i = java.net.InetAddress.getLocalHost(); System.out.println(i); // name and IP address System.out.println(i.getHostName()); // name System.out.println(i.getHostAddress()); // IP address only } catch(Exception e){e.printStackTrace();} } }
The output:
> java NetInfo realone/209.142.72.112 realone 209.142.72.112
To list all the interfaces available on a workstation:
import java.net.*; import java.util.*; import java.io.*; import java.nio.*; public class IPAdress { public void getInterfaces (){ try { Enumeration e = NetworkInterface.getNetworkInterfaces(); while(e.hasMoreElements()) { NetworkInterface ni = (NetworkInterface) e.nextElement(); System.out.println("Net interface: "+ni.getName()); Enumeration e2 = ni.getInetAddresses(); while (e2.hasMoreElements()){ InetAddress ip = (InetAddress) e2.nextElement(); System.out.println("IP address: "+ ip.toString()); } } } catch (Exception e) { e.printStackTrace(); } } public static void main(String[] args) { IPAdress ip = new IPAdress(); ip.getInterfaces(); } }
The output:
> java IPAdress Net interface: lo IP address: /127.0.0.1 Net interface: eth0 IP address: /194.168.0.1 Net interface: eth1 IP address: /164.254.147.20 Net interface: ppp0 IP address: /64.68.115.69
Windows
A “low-tech” way to get the computer name (can be useful if there is no network card) is to use the environment variable COMPUTERNAME (at least on modern Windows installation).
[JDK1.4 or less] Pass it to your JVM as java -Dcomputername=”%COMPUTERNAME%” … and then get the value with System.getProperty(“computername”)
[JDK1.5 or more] You can extract environment variables directly with System.getenv(“COMPUTERNAME”)
Done! Happy coding!
Related posts:
Java Program to Find Number of Spanning Trees in a Complete Bipartite Graph
Tạo ứng dụng Java RESTful Client không sử dụng 3rd party libraries
Java Program to Implement Segment Tree
Remove the First Element from a List
Introduction to Spring Data MongoDB
Java Program to Implement Hamiltonian Cycle Algorithm
ETags for REST with Spring
An Introduction to Java.util.Hashtable Class
Marker Interface trong Java
Java Program to Implement Interpolation Search Algorithm
Spring Boot - Tomcat Deployment
Server-Sent Events in Spring
Java Program to Find All Pairs Shortest Path
Sending Emails with Java
Java Program to Implement Miller Rabin Primality Test Algorithm
Java Program to Implement CopyOnWriteArrayList API
Lập trình mạng với java
Custom Thread Pools In Java 8 Parallel Streams
Guide to System.gc()
Java Program to Find SSSP (Single Source Shortest Path) in DAG (Directed Acyclic Graphs)
Java Program to implement Dynamic Array
Hướng dẫn Java Design Pattern – MVC
Difference Between Wait and Sleep in Java
Hướng dẫn Java Design Pattern – Factory Method
Java Program to Implement Johnson’s Algorithm
Các nguyên lý thiết kế hướng đối tượng – SOLID
Java Program to Implement Caesar Cypher
Java Program to Implement Regular Falsi Algorithm
Removing all Nulls from a List in Java
Java Program to Implement CountMinSketch
Java 8 – Powerful Comparison with Lambdas
Hashing a Password in Java