java 获取IP地址

package util;

import java.net.InetAddress;
import java.net.UnknownHostException;

import javax.servlet.http.HttpServletRequest;

public class CusAccessObjectUtil {

/**
* 获取用户真实IP地址，不使用request.getRemoteAddr();的原因是有可能用户使用了代理软件方式避免真实IP地址,
* 参考文章： http://developer.51cto.com/art/201111/305181.htm
*
* 可是，如果通过了多级反向代理的话，X-Forwarded-For的值并不止一个，而是一串IP值，究竟哪个才是真正的用户端的真实IP呢？
* 答案是取X-Forwarded-For中第一个非unknown的有效IP字符串。
*
* 如：X-Forwarded-For：192.168.1.110, 192.168.1.120, 192.168.1.130,
* 192.168.1.100
*
* 用户真实IP为： 192.168.1.110
*
* @param request
* @return
*/
public static String getIpAddress(HttpServletRequest request) {
String ipAddress = request.getHeader("x-forwarded-for");
if(ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) {
ipAddress = request.getHeader("Proxy-Client-IP");
}
if(ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) {
ipAddress = request.getHeader("WL-Proxy-Client-IP");
}
if(ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) {
ipAddress = request.getRemoteAddr();
if(ipAddress.equals("127.0.0.1") || ipAddress.equals("0:0:0:0:0:0:0:1")){
//根据网卡取本机配置的IP
InetAddress inet=null;
try {
inet = InetAddress.getLocalHost();
} catch (UnknownHostException e) {
e.printStackTrace();
}
ipAddress= inet.getHostAddress();
}
}
//对于通过多个代理的情况，第一个IP为客户端真实IP,多个IP按照','分割
if(ipAddress!=null && ipAddress.length()>15){ //"***.***.***.***".length() = 15
if(ipAddress.indexOf(",")>0){
ipAddress = ipAddress.substring(0,ipAddress.indexOf(","));
}
}
return ipAddress;
}


public static String getLocalIP() throws UnknownHostException {
String localIP = "";
InetAddress addr = (InetAddress) InetAddress.getLocalHost();

localIP = addr.getHostAddress().toString();
return localIP;
}


}