1.  private String getClientIpAddr(HttpServletRequest request) {
    2.     String ip = request.getHeader("X-Forwarded-For");  
    3.     if (ip == null || ip.length() == 0 || ip.equalsIgnoreCase("unknown")) {  
    4.         ip = request.getHeader("Proxy-Client-IP");  
    5.     }  
    6.     if (ip == null || ip.length() == 0 || ip.equalsIgnoreCase("unknown")) {  
    7.         ip = request.getHeader("WL-Proxy-Client-IP");  
    8.     }  
    9.     if (ip == null || ip.length() == 0 || ip.equalsIgnoreCase("unknown")) {  
    10.         ip = request.getHeader("HTTP_X_FORWARDED_FOR");  
    11.     }  
    12.     if (ip == null || ip.length() == 0 || ip.equalsIgnoreCase("unknown")) {  
    13.         ip = request.getHeader("HTTP_X_FORWARDED");  
    14.     }  
    15.     if (ip == null || ip.length() == 0 || ip.equalsIgnoreCase("unknown")) {  
    16.         ip = request.getHeader("HTTP_X_CLUSTER_CLIENT_IP");  
    17.     }  
    18.     if (ip == null || ip.length() == 0 || ip.equalsIgnoreCase("unknown")) {  
    19.         ip = request.getHeader("HTTP_CLIENT_IP");  
    20.     }  
    21.     if (ip == null || ip.length() == 0 || ip.equalsIgnoreCase("unknown")) {  
    22.         ip = request.getHeader("HTTP_FORWARDED_FOR");  
    23.     }  
    24.     if (ip == null || ip.length() == 0 || ip.equalsIgnoreCase("unknown")) {  
    25.         ip = request.getHeader("HTTP_FORWARDED");  
    26.     }  
    27.     if (ip == null || ip.length() == 0 || ip.equalsIgnoreCase("unknown")) {  
    28.         ip = request.getHeader("HTTP_VIA");  
    29.     }  
    30.     if (ip == null || ip.length() == 0 || ip.equalsIgnoreCase("unknown")) {  
    31.         ip = request.getHeader("REMOTE_ADDR");  
    32.     }  
    33.     if (ip == null || ip.length() == 0 || ip.equalsIgnoreCase("unknown")) {  
    34.         ip = request.getRemoteAddr();  
    35.     }  
    36.     return ip;  
    37. }