多级代理下获取客户端真实IP

 1    /**
 2      * 获取当前网络ip
 3      * @param request
 4      * @return
 5      */
 6     public String getIpAddr(HttpServletRequest request){
 7         String ipAddress = request.getHeader("x-forwarded-for");
 8         if(ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) {
 9             ipAddress = request.getHeader("Proxy-Client-IP");
10         }
11         if(ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) {
12             ipAddress = request.getHeader("WL-Proxy-Client-IP");
13         }
14         if(ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) {
15             ipAddress = request.getRemoteAddr();
16             if(ipAddress.equals("127.0.0.1") || ipAddress.equals("0:0:0:0:0:0:0:1")){
17                 //根据网卡取本机配置的IP
18                 InetAddress inet=null;
19                 try {
20                     inet = InetAddress.getLocalHost();
21                 } catch (UnknownHostException e) {
22                     e.printStackTrace();
23                 }
24                 ipAddress= inet.getHostAddress();
25             }
26         }
27         //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
28         if(ipAddress!=null && ipAddress.length()>15){ //"***.***.***.***".length() = 15
29             if(ipAddress.indexOf(",")>0){
30                 ipAddress = ipAddress.substring(0,ipAddress.indexOf(","));
31             }
32         }
33         return ipAddress;
34     }