public final class NetUtil
extends java.lang.Object

• Field Summary

  Fields

  Modifier and Type	Field and Description
  static java.net.InetAddress	LOCALHOST The InetAddress that represents the loopback address.
  static java.net.Inet4Address	LOCALHOST4 The Inet4Address that represents the IPv4 loopback address '127.0.0.1'
  static java.net.Inet6Address	LOCALHOST6 The Inet6Address that represents the IPv6 loopback address '::1'
  static java.net.NetworkInterface	LOOPBACK_IF The loopback NetworkInterface of the current machine
  static int	SOMAXCONN The SOMAXCONN value of the current machine.

• Method Summary

  All Methods

  Modifier and Type	Method and Description
  static byte[]	createByteArrayFromIpAddressString (java.lang.String ipAddressString) Creates an byte[] based on an ipAddressString.
  static java.net.Inet6Address	getByName (java.lang.CharSequence ip) Returns the Inet6Address representation of a CharSequence IP address.
  static java.net.Inet6Address	getByName (java.lang.CharSequence ip, boolean ipv4Mapped) Returns the Inet6Address representation of a CharSequence IP address.
  static boolean	isIpV4StackPreferred () Returns true if ipv4 should be prefered on a system that supports ipv4 and ipv6.
  static boolean	isValidIpV4Address (java.lang.String ip) Takes a string and parses it to see if it is a valid IPV4 address.
  static boolean	isValidIpV6Address (java.lang.String ip)
  static java.lang.String	toAddressString (java.net.InetAddress ip) Returns the String representation of an InetAddress.
  static java.lang.String	toAddressString (java.net.InetAddress ip, boolean ipv4Mapped) Returns the String representation of an InetAddress.
  static java.lang.String	toSocketAddressString (java.net.InetSocketAddress addr) Returns the String representation of an InetSocketAddress.
  static java.lang.String	toSocketAddressString (java.lang.String host, int port) Returns the String representation of a host port combo.

  • Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

• Field Detail

  • LOCALHOST4

    public static final java.net.Inet4Address LOCALHOST4

    The Inet4Address that represents the IPv4 loopback address '127.0.0.1'

  • LOCALHOST6

    public static final java.net.Inet6Address LOCALHOST6

    The Inet6Address that represents the IPv6 loopback address '::1'

  • LOCALHOST

    public static final java.net.InetAddress LOCALHOST

    The InetAddress that represents the loopback address. If IPv6 stack is available, it will refer to LOCALHOST6. Otherwise, LOCALHOST4.

  • LOOPBACK_IF

    public static final java.net.NetworkInterface LOOPBACK_IF

    The loopback NetworkInterface of the current machine

  • SOMAXCONN

    public static final int SOMAXCONN

    The SOMAXCONN value of the current machine. If failed to get the value, 200 is used as a default value for Windows or 128 for others.

• Method Detail

  • isIpV4StackPreferred

    public static boolean isIpV4StackPreferred()

    Returns true if ipv4 should be prefered on a system that supports ipv4 and ipv6.

  • createByteArrayFromIpAddressString

    public static byte[] createByteArrayFromIpAddressString(java.lang.String ipAddressString)

    Creates an byte[] based on an ipAddressString. No error handling is performed here.

  • isValidIpV6Address

    public static boolean isValidIpV6Address(java.lang.String ip)

  • isValidIpV4Address

    public static boolean isValidIpV4Address(java.lang.String ip)

    Takes a string and parses it to see if it is a valid IPV4 address.

    Returns:

    true, if the string represents an IPV4 address in dotted notation, false otherwise

  • getByName

    public static java.net.Inet6Address getByName(java.lang.CharSequence ip)

    Returns the Inet6Address representation of a CharSequence IP address.

    This method will treat all IPv4 type addresses as "IPv4 mapped" (see getByName(CharSequence, boolean))

    Parameters:

    ip - CharSequence IP address to be converted to a Inet6Address

    Returns:

    Inet6Address representation of the ip or null if not a valid IP address.

  • getByName

    public static java.net.Inet6Address getByName(java.lang.CharSequence ip,
     boolean ipv4Mapped)

    Returns the Inet6Address representation of a CharSequence IP address.

    The ipv4Mapped parameter specifies how IPv4 addresses should be treated. "IPv4 mapped" format as defined in rfc 4291 section 2 is supported.

    Parameters:

    ip - CharSequence IP address to be converted to a Inet6Address

    ipv4Mapped -

    • true To allow IPv4 mapped inputs to be translated into Inet6Address
    • false Consider IPv4 mapped addresses as invalid.

    Returns:

    Inet6Address representation of the ip or null if not a valid IP address.

  • toSocketAddressString

    public static java.lang.String toSocketAddressString(java.net.InetSocketAddress addr)

    Returns the String representation of an InetSocketAddress.

    The output does not include Scope ID.

    Parameters:

    addr - InetSocketAddress to be converted to an address string

    Returns:

    String containing the text-formatted IP address

  • toSocketAddressString

    public static java.lang.String toSocketAddressString(java.lang.String host,
     int port)

    Returns the String representation of a host port combo.

  • toAddressString

    public static java.lang.String toAddressString(java.net.InetAddress ip)

    Returns the String representation of an InetAddress.

    • Inet4Address results are identical to InetAddress.getHostAddress()
    • Inet6Address results adhere to rfc 5952 section 4

    The output does not include Scope ID.

    Parameters:

    ip - InetAddress to be converted to an address string

    Returns:

    String containing the text-formatted IP address

  • toAddressString

    public static java.lang.String toAddressString(java.net.InetAddress ip,
     boolean ipv4Mapped)

    Returns the String representation of an InetAddress.

    • Inet4Address results are identical to InetAddress.getHostAddress()
    • Inet6Address results adhere to rfc 5952 section 4 if ipv4Mapped is false. If ipv4Mapped is true then "IPv4 mapped" format from rfc 4291 section 2 will be supported. The compressed result will always obey the compression rules defined in rfc 5952 section 4

    The output does not include Scope ID.

    Parameters:

    ip - InetAddress to be converted to an address string

    ipv4Mapped -

    • true to stray from strict rfc 5952 and support the "IPv4 mapped" format defined in rfc 4291 section 2 while still following the updated guidelines in rfc 5952 section 4
    • false to strictly follow rfc 5952

    Returns:

    String containing the text-formatted IP address