综合了网上找的代码，整理的，Windows和Linux都可以用。

	private static String getHostIp(){
		try{
			Enumeration<NetworkInterface> allNetInterfaces = NetworkInterface.getNetworkInterfaces();
			while (allNetInterfaces.hasMoreElements()){
				NetworkInterface netInterface = (NetworkInterface) allNetInterfaces.nextElement();
				Enumeration<InetAddress> addresses = netInterface.getInetAddresses();
				while (addresses.hasMoreElements()){
					InetAddress ip = (InetAddress) addresses.nextElement();
					if (ip != null 
							&& ip instanceof Inet4Address
                    		&& !ip.isLoopbackAddress() //loopback地址即本机地址，IPv4的loopback范围是127.0.0.0 ~ 127.255.255.255
                    		&& ip.getHostAddress().indexOf(":")==-1){
						System.out.println("本机的IP = " + ip.getHostAddress());
						return ip.getHostAddress();
					} 
				}
			}
		}catch(Exception e){
			e.printStackTrace();
		}
		return null;
	}