/**
	 * 从request中获取请求方IP
	 * @param request
	 * @return
	 */
	public static String getIpAddress(HttpServletRequest request) {  
        String ip = request.getHeader("x-forwarded-for");  
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {  
            ip = request.getHeader("Proxy-Client-IP");  
         }  
         if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {  
            ip = request.getHeader("WL-Proxy-Client-IP");  
         }  
         if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {  
             ip = request.getHeader("HTTP_CLIENT_IP");  
         }  
         if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {  
            ip = request.getHeader("HTTP_X_FORWARDED_FOR");  
         }  
         if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {  
             ip = request.getRemoteAddr();  
         }  
         return ip;  
     }