How To Check Network Connection Using Java

It if often required to get the details of the network connection in your desktop. It will be useful if you could get the details of all the connected network details for the future operations. Java has set of classes in the java.net package which is useful for the Java network programming. In this example I have used NetworkInterface class to get the list of networks connected to the system. It doesn’t provide the network is internet or intranet, but you will be able to use the details to get an idea about the network connection.

Lets look at the example.

NetworkConnectionExample.java

package javabeat.net.core;

import java.io.IOException;
import java.net.InterfaceAddress;
import java.net.NetworkInterface;
import java.net.UnknownHostException;
import java.util.Enumeration;

public class NetworkConnectionExample {
	public static void main(String[] args) throws UnknownHostException, IOException{
		Enumeration<NetworkInterface> interfaces = NetworkInterface.getNetworkInterfaces();
		while (interfaces.hasMoreElements()) {
		    NetworkInterface networkInterface = interfaces.nextElement();
		    System.out.println("Network Interface Name : [" + networkInterface.getDisplayName() + "]");
		    System.out.println("Is It connected? : [" + networkInterface.isUp() + "]");
		    for (InterfaceAddress i : networkInterface.getInterfaceAddresses()){
		    	System.out.println("Host Name : "+i.getAddress().getCanonicalHostName());
		    	System.out.println("Host Address : "+i.getAddress().getHostAddress());
		    }
		    System.out.println("----------------------");
		}
	}
}

Output…

Network Interface Name : [eth1]
Is It connected? : [true]
Host Name : fe80:0:0:0:2e0:4cff:fe00:2071%3
Host Address : fe80:0:0:0:2e0:4cff:fe00:2071%3
Host Name : krishna-desktop.local
Host Address : 192.168.0.101
----------------------
Network Interface Name : [lo]
Is It connected? : [true]
Host Name : ip6-localhost
Host Address : 0:0:0:0:0:0:0:1%1
Host Name : localhost
Host Address : 127.0.0.1
----------------------