得到客户端的IP

 /**
    * 得到Ip地址
    * @param request
    * @return
    */
   public String getIpAddr(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.getRemoteAddr();  
	     }  
	     return ip;  
	}