获取本机ip, 获取远程请求的主机IP地址, 判断当前操作系统

包含:

• 获取请求主机IP地址,如果通过代理进来，则透过防火墙获取真实IP地址
• 获取本地IP地址
• 判断操作系统是否是Windows
  

import lombok.extern.log4j.Log4j;

import javax.servlet.http.HttpServletRequest;
import java.net.InetAddress;
import java.net.NetworkInterface;
import java.net.SocketException;
import java.net.UnknownHostException;
import java.util.Enumeration;

/**
 * Created by wyh on 16/12/19.
 */
@Log4j
public final class NetworkUtil {

    /**
     * 获取请求主机IP地址,如果通过代理进来，则透过防火墙获取真实IP地址;
     *
     * @param request
     * @return
     * @throws
     */
    public final static String getIpAddress(HttpServletRequest request) {
        // 获取请求主机IP地址,如果通过代理进来，则透过防火墙获取真实IP地址

        String ip = request.getHeader("X-Forwarded-For");
        if (log.isInfoEnabled()) {
            log.info("getIpAddress(HttpServletRequest) - X-Forwarded-For - String ip=" + ip);
        }

        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
                ip = request.getHeader("Proxy-Client-IP");
                if (log.isInfoEnabled()) {
                    log.info("getIpAddress(HttpServletRequest) - Proxy-Client-IP - String ip=" + ip);
                }
            }
            if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
                ip = request.getHeader("WL-Proxy-Client-IP");
                if (log.isInfoEnabled()) {
                    log.info("getIpAddress(HttpServletRequest) - WL-Proxy-Client-IP - String ip=" + ip);
                }
            }
            if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
                ip = request.getHeader("HTTP_CLIENT_IP");
                if (log.isInfoEnabled()) {
                    log.info("getIpAddress(HttpServletRequest) - HTTP_CLIENT_IP - String ip=" + ip);
                }
            }
            if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
                ip = request.getHeader("HTTP_X_FORWARDED_FOR");
                if (log.isInfoEnabled()) {
                    log.info("getIpAddress(HttpServletRequest) - HTTP_X_FORWARDED_FOR - String ip=" + ip);
                }
            }
            if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
                ip = request.getRemoteAddr();
                if (log.isInfoEnabled()) {
                    log.info("getIpAddress(HttpServletRequest) - getRemoteAddr - String ip=" + ip);
                }
            }
        } else if (ip.length() > 15) {
            String[] ips = ip.split(",");
            for (int index = 0; index < ips.length; index++) {
                String strIp = (String) ips[index];
                if (!("unknown".equalsIgnoreCase(strIp))) {
                    ip = strIp;
                    break;
                }
            }
        }
        return ip;
    }



    /**
     * 获取本地IP地址
     *
     * @throws SocketException
     */
    public static String getLocalIP() {
        try {
            if (isWindowsOS()) {
                return InetAddress.getLocalHost().getHostAddress();
            } else {
                return getLinuxLocalIp();
            }
        } catch (UnknownHostException e) {
            e.printStackTrace();
            log.error("获取ip地址异常", e);
        }
        return "";
    }

    /**
     * 获取Linux下的IP地址
     *
     * @return IP地址
     * @throws SocketException
     */
    private static String getLinuxLocalIp() {
        String ip = "";
        try {
            for (Enumeration<NetworkInterface> en = NetworkInterface.getNetworkInterfaces(); en.hasMoreElements(); ) {
                NetworkInterface intf = en.nextElement();
                String name = intf.getName();
                if (!name.contains("docker") && !name.contains("lo")) {
                    for (Enumeration<InetAddress> enumIpAddr = intf.getInetAddresses(); enumIpAddr.hasMoreElements(); ) {
                        InetAddress inetAddress = enumIpAddr.nextElement();
                        if (!inetAddress.isLoopbackAddress()) {
                            String ipaddress = inetAddress.getHostAddress().toString();
                            if (!ipaddress.contains("::") && !ipaddress.contains("0:0:") && !ipaddress.contains("fe80")) {
                                ip = ipaddress;
                            }
                        }
                    }
                }
            }
        } catch (SocketException ex) {
            log.error("获取ip地址异常", ex);
            ip = "127.0.0.1";
            ex.printStackTrace();
        }
        return ip;
    }

    /**
     * 判断操作系统是否是Windows
     *
     * @return
     */
    public static boolean isWindowsOS() {
        boolean isWindowsOS = false;
        String osName = System.getProperty("os.name");
        if (osName.toLowerCase().indexOf("windows") > -1) {
            isWindowsOS = true;
        }
        return isWindowsOS;
    }

    /**
     * 获取本地Host名称
     */
    public static String getLocalHostName() throws UnknownHostException {
        return InetAddress.getLocalHost().getHostName();
    }

    public static boolean isIpv4(String ipv4){
        if(ipv4==null || ipv4.length()==0){
            return false;//字符串为空或者空串
        }
        String[] parts=ipv4.split("\\.");//因为java doc里已经说明, split的参数是reg, 即正则表达式, 如果用"|"分割, 则需使用"\\|"
        if(parts.length!=4){
            return false;//分割开的数组根本就不是4个数字
        }
        for(int i=0;i<parts.length;i++){
            try{
                int n=Integer.parseInt(parts[i]);
                if(n<0 || n>255){
                    return false;//数字不在正确范围内
                }
            }catch (NumberFormatException e) {
                return false;//转换数字不正确
            }
        }
        return true;
    }

}