Module java.base
Package java.net.spi

Class InetAddressResolver.LookupPolicy

java.lang.Object
java.net.spi.InetAddressResolver.LookupPolicy
Enclosing interface:
InetAddressResolver
public static final class InetAddressResolver.LookupPolicy extends Object
A LookupPolicy object describes characteristics that can be applied to a lookup operation. In particular, it is used to specify the ordering and which filtering should be performed when looking up host addresses.

The default platform-wide lookup policy is constructed by consulting System Properties which affect how IPv4 and IPv6 addresses are returned.

Since:
18

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final int
    IPV4
    Characteristic value signifying if IPv4 addresses need to be queried during lookup.
    static final int
    IPV4_FIRST
    Characteristic value signifying if IPv4 addresses should be returned first by InetAddressResolver.
    static final int
    IPV6
    Characteristic value signifying if IPv6 addresses need to be queried during lookup.
    static final int
    IPV6_FIRST
    Characteristic value signifying if IPv6 addresses should be returned first by InetAddressResolver.

  • Method Summary

    Modifier and Type
    Method
    Description
    int
    characteristics()
    Returns the set of characteristics of this lookup policy.
    static InetAddressResolver.LookupPolicy
    of(int characteristics)
    This factory method creates a LookupPolicy instance with the given characteristics value.

    Methods declared in class java.lang.Object

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

  • Field Details

    • IPV4

      @Native public static final int IPV4
      Characteristic value signifying if IPv4 addresses need to be queried during lookup.
      See Also:

    • IPV6

      @Native public static final int IPV6
      Characteristic value signifying if IPv6 addresses need to be queried during lookup.
      See Also:

    • IPV4_FIRST

      @Native public static final int IPV4_FIRST
      Characteristic value signifying if IPv4 addresses should be returned first by InetAddressResolver.
      See Also:

    • IPV6_FIRST

      @Native public static final int IPV6_FIRST
      Characteristic value signifying if IPv6 addresses should be returned first by InetAddressResolver.
      See Also:

  • Method Details

    • of

      public static InetAddressResolver.LookupPolicy of(int characteristics)
      This factory method creates a LookupPolicy instance with the given characteristics value.

      The characteristics value is an integer bit mask which defines parameters of a forward lookup operation. These parameters define at least:

      • the family type of the returned addresses
      • the order in which a resolver implementation should return its results

      To request addresses of specific family types the following bit masks can be combined:

      • IPV4: to request IPv4 addresses
      • IPV6: to request IPv6 addresses

      It is an error if neither IPV4 or IPV6 are set.

      To request a specific ordering of the results:

      • IPV4_FIRST: return IPv4 addresses before any IPv6 address
      • IPV6_FIRST: return IPv6 addresses before any IPv4 address

      If neither IPV4_FIRST or IPV6_FIRST are set it implies "system" order of addresses. It is an error to request both IPV4_FIRST and IPV6_FIRST.
      Parameters:
      characteristics - a value which represents the set of lookup characteristics
      Returns:
      an instance of InetAddressResolver.LookupPolicy
      Throws:
      IllegalArgumentException - if an illegal characteristics bit mask is provided
      See Also:

    • characteristics

      public int characteristics()
      Returns the set of characteristics of this lookup policy.
      Returns:
      a characteristics value
      See Also: