Simply call InetAddress.getByName(String host) passing in your textual IP address.
From the javadoc: The host name can either be a machine name, such as "java.sun.com", or a textual representation of its IP address.
// print the IP Address of your machine (inside your local network)
System.out.println(InetAddress.getLocalHost().getHostAddress());
// print the IP Address of a web site
System.out.println(InetAddress.getByName("www.javacodegeeks.com"));
// print all the IP Addresses that are assigned to a certain domain
InetAddress[] inetAddresses = InetAddress.getAllByName("www.google.com");
for (InetAddress ipAddress : inetAddresses) {
System.out.println(ipAddress);
}