Java.net.InterfaceAddress class in Java

This class represents a network interface address. Every device that has an IP address has an IP address on the network interface. In fact the ping command doesn't ping a device but the devices interface address. Java provides certain methods to deal with interface addresses which can be used in places where there is a need to know the topology of the network, for fault detection in a network etc.
Methods :

1. getAddress() : Returns an InetAddress for this address.

Syntax : public InetAddress getAddress()

1. getBroadcast() : Returns the InetAddress for the broadcast address for this interface address. As only IPv4 addresses have broadcast addresses, null would be returned on using an IPv6 address.

Syntax :public InetAddress getBroadcast()

1. getNetworkPrefixLength() : Returns the prefix length for this interface address, i.e. subnet mask for this address.

Syntax :public short getNetworkPrefixLength()

1. equals() : Used for comparison of the specified object with this interface address. Returns true only if the given object is not null and represents same interface address as this object.

Syntax :public boolean equals(Object obj)
Parameters :
obj : obj to compare with

1. hashCode() : Returns the hashcode for this interface address. 

Syntax :public int hashCode()

1. toString() : Returns a string representation of this interface address. The string is of the form : Interface Address/ prefix length.

Syntax :public String toString()

Java Implementation :

// Java program to illustrate methods of 
// Java.net.InterfaceAddress class
import java.net.InterfaceAddress;
import java.net.NetworkInterface;
import java.net.SocketException;
import java.util.List;

public class interfaceaddress 
{
    public static void main(String[] args) throws SocketException 
    {
        // Modify according to your system
        NetworkInterface nif = NetworkInterface.getByIndex(1);
        List<InterfaceAddress> list = nif.getInterfaceAddresses();

        for (InterfaceAddress iaddr : list) 
        {

            // getAddress() method
            System.out.println("getAddress() : " + iaddr.getAddress());

            // getBroadcast() method
            System.out.println("getBroadcast() : " + iaddr.getBroadcast());

            // getNetworkPrefixLength() method
            System.out.println("PrefixLength : " + iaddr.getNetworkPrefixLength());

            // hashCode() method
            System.out.println("Hashcode : " + iaddr.hashCode());

            // toString() method
            System.out.println("toString() : " + iaddr.toString());

            System.out.println("--------------------\n");
        }
    }

}

Output :

getAddress() : /127.0.0.1
getBroadcast() : /127.255.255.255
PrefixLength : 8
Hashcode : -16777208
toString() : /127.0.0.1/8 [/127.255.255.255]
--------------------

getAddress() : /0:0:0:0:0:0:0:1
getBroadcast() : null
PrefixLength : 128
Hashcode : 129
toString() : /0:0:0:0:0:0:0:1/128 [null]
--------------------

Please modify the index in getbyIndex() method in the above program as the network interface at index 1 might be null in your system. For more details about the this method, refer to- java.net.NetworkInterface class
References :
Official Java Documentation