对于恰好用一个掩码表示的段, 返回一个段, 例如[quote]58.246.0.0 - 58.247.255.255[/quote] -> [quote]58.246.0.0/15[/quote]
对于不能用一个掩码表示的端, 会返回一系列段. 例如[quote]0.0.0.0 - 0.0.5.128[/quote] -> [quote]0.0.0.0/22;0.0.4.0/24;0.0.5.0/25;0.0.5.128/32;[/quote]
public static long ip2long(String strIP) { try { long[] ip = new long[4]; int position1 = strIP.indexOf("."); int position2 = strIP.indexOf(".", position1 + 1); int position3 = strIP.indexOf(".", position2 + 1); 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]; } catch (Exception e) { return 0; } } public static String long2ip(long longIP) { return new StringBuffer(String.valueOf(longIP >>> 24)).append(".") .append(String.valueOf((longIP & 0x00FFFFFF) >>> 16)).append(".") .append(String.valueOf((longIP & 0x0000FFFF) >>> 8)).append(".") .append(String.valueOf(longIP & 0x000000FF)).toString(); } public static Map<String, Integer> ipBlock2mask(String startIps, String endIps) { Map<String, Integer> blocks = new LinkedHashMap<String, Integer>(); int mask = 32; long startIp = ip2long(startIps), endIp = ip2long(endIps) + 1; while (true) { if (startIp + new Double(Math.pow(2, 32 - mask)).longValue() > endIp) { // found the mask mask++; blocks.put(startIps, mask); long newStartIp = startIp + new Double(Math.pow(2, 32 - mask)).longValue(); if (newStartIp >= endIp) { break; // exit all } else { startIp = newStartIp; startIps = long2ip(startIp); mask = 32; } } mask--; } return blocks; } // 0.0.0.0 - 0.0.5.128 => 0.0.0.0/22;0.0.4.0/24;0.0.5.0/25;0.0.5.128/32; // 0.0.0.0 - 0.0.5.255 => 0.0.0.0/22;0.0.4.0/23; public static String ipBlock2maskString(String startIps, String endIps) { Map<String, Integer> blocks = ipBlock2mask(startIps, endIps); StringBuilder sb = new StringBuilder(); for (Map.Entry<String, Integer> entry : blocks.entrySet()) { sb.append(entry.getKey()).append("/").append(entry.getValue()).append(";"); } return sb.toString(); }
