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:

• Constant Field Values

IPV6

@Native
public static final int IPV6

Characteristic value signifying if IPv6 addresses need to be queried during lookup.

See Also:

• Constant Field Values

IPV4_FIRST

@Native
public static final int IPV4_FIRST

Characteristic value signifying if IPv4 addresses should be returned first by InetAddressResolver.

See Also:

• Constant Field Values

IPV6_FIRST

@Native
public static final int IPV6_FIRST

Characteristic value signifying if IPv6 addresses should be returned first by InetAddressResolver.

See Also:

• Constant Field Values

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:

• InetAddressResolver.lookupByName(String, LookupPolicy)

characteristics

public int characteristics()

Returns the set of characteristics of this lookup policy.

Returns:

a characteristics value

See Also:

• InetAddressResolver.lookupByName(String, LookupPolicy)