Java和IP-子网解析

Question

Is there an easy way in java to get the range of an IP from the format of

175.25.0.0/16

to somewhat like 175.25.0.0-175.25.255.255

Answer 1

public String getHostAddressRange(String netmaskNumeric) {

  int numberOfBits; for (numberOfBits = 0; numberOfBits < 32; numberOfBits++) { if ((netmaskNumeric << numberOfBits) == 0) break; } Integer numberOfIPs = 0; for (int n = 0; n < (32 - numberOfBits); n++) { numberOfIPs = numberOfIPs << 1; numberOfIPs = numberOfIPs | 0x01; } Integer baseIP = baseIPnumeric & netmaskNumeric; String firstIP = convertNumericIpToSymbolic(baseIP + 1); String lastIP = convertNumericIpToSymbolic(baseIP + numberOfIPs - 1); return firstIP + " - " + lastIP; }