IP转换10进制

public static long ipToLong(String strIp) {
   long[] ip = new long[4];
   // 先找到IP地址字符串中.的位置
   int position1 = strIp.indexOf(".");
   int position2 = strIp.indexOf(".", position1 + 1);
   int position3 = strIp.indexOf(".", position2 + 1);
   // 将每个.之间的字符串转换成整型
   ip[0] = Long.parseLong(strIp.substring(0, position1));
   ip[1] = Long.parseLong(strIp.substring(position1 + 1, position2));
   ip[2] = Long.parseLong(strIp.substring(position2 + 1, position3));
   ip[3] = Long.parseLong(strIp.substring(position3 + 1));
   return (ip[0] << 24) + (ip[1] << 16) + (ip[2] << 8) + ip[3];
}

获取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;
	}

 

 

 // 将十进制整数形式转换成127.0.0.1形式的ip地址

 

public static String longToIP(long longIp) {
   StringBuffer sb = new StringBuffer("");
   // 直接右移24位
   sb.append(String.valueOf((longIp >>> 24)));
   sb.append(".");
   // 将高8位置0，然后右移16位
   sb.append(String.valueOf((longIp & 0x00FFFFFF) >>> 16));
   sb.append(".");
   // 将高16位置0，然后右移8位
   sb.append(String.valueOf((longIp & 0x0000FFFF) >>> 8));
   sb.append(".");
   // 将高24位置0
   sb.append(String.valueOf((longIp & 0x000000FF)));
   return sb.toString();
}