NetUtil.java Source code

Introduction

Here is the source code for NetUtil.java

Source

// Copyright (c) 2003-2009, Jodd Team (jodd.org). All Rights Reserved.

import java.io.IOException;
import java.net.HttpURLConnection;
import java.net.Inet4Address;
import java.net.InetAddress;
import java.net.URL;
import java.net.UnknownHostException;

/**
 * Network utilities.
 */
public class NetUtil {

    /**
     * Resolves hostname and returns ip address as a string.
     */
    public static String resolveHost(String hostname) {
        try {
            InetAddress addr = Inet4Address.getByName(hostname);
            byte[] ipAddr = addr.getAddress();
            StringBuilder ipAddrStr = new StringBuilder(15);
            for (int i = 0; i < ipAddr.length; i++) {
                if (i > 0) {
                    ipAddrStr.append('.');
                }
                ipAddrStr.append(ipAddr[i] & 0xFF);
            }
            return ipAddrStr.toString();
        } catch (UnknownHostException uhex) {
            return null;
        }
    }

    /**
     * Resolves string ip address and returns host name as a string.
     */
    public static String resolveIp(String ip) {
        try {
            InetAddress addr = InetAddress.getByName(ip);
            return addr.getHostName();
        } catch (UnknownHostException uhex) {
            return null;
        }
    }

    /**
     * Resolves ip address and returns host name as a string.
     */
    public static String resolveIp(byte[] ip) {
        try {
            InetAddress addr = InetAddress.getByAddress(ip);
            return addr.getHostName();
        } catch (UnknownHostException uhex) {
            return null;
        }
    }

}