获取用户IP地址，防钓鱼

public static String getClientIP(HttpServletRequest httpservletrequest) {
if (httpservletrequest == null)
return null;
String s = httpservletrequest.getHeader("X-Forwarded-For");
if (s == null || s.length() == 0 || "unknown".equalsIgnoreCase(s))
s = httpservletrequest.getHeader("Proxy-Client-IP");
if (s == null || s.length() == 0 || "unknown".equalsIgnoreCase(s))
s = httpservletrequest.getHeader("WL-Proxy-Client-IP");
if (s == null || s.length() == 0 || "unknown".equalsIgnoreCase(s))
s = httpservletrequest.getHeader("HTTP_CLIENT_IP");
if (s == null || s.length() == 0 || "unknown".equalsIgnoreCase(s))
s = httpservletrequest.getHeader("HTTP_X_FORWARDED_FOR");
if (s == null || s.length() == 0 || "unknown".equalsIgnoreCase(s))
s = httpservletrequest.getRemoteAddr();
if ("127.0.0.1".equals(s) || "0:0:0:0:0:0:0:1".equals(s))
try {
s = InetAddress.getLocalHost().getHostAddress();
}catch (UnknownHostException uhe) {
19          uhe.printStackTrace();
20       }
return s;
}