import java.util.regex.Pattern; import org.apache.http.annotation.Immutable; /** * A collection of utilities relating to InetAddresses. * * @since 4.0 */ @Immutable public class InetAddressUtils { private InetAddressUtils() { } private static final String IPV4_BASIC_PATTERN_STRING = "(([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\.){3}" + // initial 3 fields, 0-255 followed by . "([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])"; // final field, 0-255 private static final Pattern IPV4_PATTERN = Pattern.compile("^" + IPV4_BASIC_PATTERN_STRING + "$"); private static final Pattern IPV4_MAPPED_IPV6_PATTERN = // TODO does not allow for redundant leading zeros Pattern.compile("^::[fF]{4}:" + IPV4_BASIC_PATTERN_STRING + "$"); private static final Pattern IPV6_STD_PATTERN = Pattern.compile( "^[0-9a-fA-F]{1,4}(:[0-9a-fA-F]{1,4}){7}$"); private static final Pattern IPV6_HEX_COMPRESSED_PATTERN = Pattern.compile( "^(([0-9A-Fa-f]{1,4}(:[0-9A-Fa-f]{1,4}){0,5})?)" + // 0-6 hex fields "::" + "(([0-9A-Fa-f]{1,4}(:[0-9A-Fa-f]{1,4}){0,5})?)$"); // 0-6 hex fields /* * The above pattern is not totally rigorous as it allows for more than 7 hex fields in total */ private static final char COLON_CHAR = ':'; // Must not have more than 7 colons (i.e. 8 fields) private static final int MAX_COLON_COUNT = 7; /** * Checks whether the parameter is a valid IPv4 address * * @param input the address string to check for validity * @return true if the input parameter is a valid IPv4 address */ public static boolean isIPv4Address(final String input) { return IPV4_PATTERN.matcher(input).matches(); } public static boolean isIPv4MappedIPv64Address(final String input) { return IPV4_MAPPED_IPV6_PATTERN.matcher(input).matches(); } /** * Checks whether the parameter is a valid standard (non-compressed) IPv6 address * * @param input the address string to check for validity * @return true if the input parameter is a valid standard (non-compressed) IPv6 address */ public static boolean isIPv6StdAddress(final String input) { return IPV6_STD_PATTERN.matcher(input).matches(); } /** * Checks whether the parameter is a valid compressed IPv6 address * * @param input the address string to check for validity * @return true if the input parameter is a valid compressed IPv6 address */ public static boolean isIPv6HexCompressedAddress(final String input) { int colonCount = 0; for(int i = 0; i < input.length(); i++) { if (input.charAt(i) == COLON_CHAR) { colonCount++; } } return colonCount <= MAX_COLON_COUNT && IPV6_HEX_COMPRESSED_PATTERN.matcher(input).matches(); } /** * Checks whether the parameter is a valid IPv6 address (including compressed). * * @param input the address string to check for validity * @return true if the input parameter is a valid standard or compressed IPv6 address */ public static boolean isIPv6Address(final String input) { return isIPv6StdAddress(input) || isIPv6HexCompressedAddress(input); } }