获得客户端真实IP

	/**
	 * 获得客户端真实IP
	 */
	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; 
	 }