jodd-core/src/main/java/jodd/io/NetUtil.java
public static String resolveIpAddress(final String hostname) {
		try {
			InetAddress netAddress;

			if (hostname == null || hostname.equalsIgnoreCase(LOCAL_HOST)) {
				netAddress = InetAddress.getLocalHost();
			} else {
				netAddress = Inet4Address.getByName(hostname);
			}
			return netAddress.getHostAddress();
		} catch (UnknownHostException ignore) {
			return null;
		}
	}
public static String resolveIpAddress(final String hostname) {
		try {
			InetAddress netAddress;

			if (hostname == null || hostname.equalsIgnoreCase(LOCAL_HOST)) {
				netAddress = InetAddress.getLocalHost();
			} else {
				netAddress = Inet4Address.getByName(hostname);
			}
			return netAddress.getHostAddress();
		} catch (UnknownHostException ignore) {
			return null;
		}
	}
Resolves IP address from a hostname.