nginx多次转发后获取客户请求IP

/**
	 * 
	 * @Description:获取客户端请求IP地址,解决使用nginx请求转发后不能获取问题
	 * @param @param request
	 * @param @return
	 * @return String
	 * @throws
	 */
	public String getIpAddr(HttpServletRequest request){
		String ip=request.getHeader("X-Forwarded-For");
    	String localIP = "127.0.0.1";
	    if((ip == null)||(ip.length() == 0)||(ip.equalsIgnoreCase(localIP))||"unknown".equalsIgnoreCase(ip)){
	        ip = request.getHeader("Proxy-Client-IP");
		}
	    if((ip == null)||(ip.length() == 0)||(ip.equalsIgnoreCase(localIP))||"unknown".equalsIgnoreCase(ip)){
	        ip = request.getHeader("WL-Proxy-Client-IP");
		}
	    if((ip == null)||(ip.length() == 0)||(ip.equalsIgnoreCase(localIP))||"unknown".equalsIgnoreCase(ip)){
	        ip = request.getRemoteAddr();
		}
	    if(ip!=null && ip.length()>15){
	         if(ip.indexOf(",")>0){
	             ip = ip.substring(0,ip.indexOf(","));
	         }
	     }
	    return ip;
	}