Modifier and Type	Class and Description
public static class	InetAddressResolver.LookupPolicy A `LookupPolicy` object describes characteristics that can be applied to a lookup operation.

Modifier and Type	Method and Description
public String	Returns: `String` representing the host name mapping lookupByAddress(byte[] byte array representing a raw IP address addr) Lookup the host name corresponding to the raw IP address provided.
public Stream<InetAddress>	Returns: a stream of IP addresses for the requested host lookupByName(String the specified hostname host, InetAddressResolver.LookupPolicy the address lookup policy lookupPolicy) Given the name of a host, returns a stream of IP addresses of the requested address family associated with a provided hostname.

Method Detail

lookupByAddress back to summary

lookupByAddress	back to summary
public String lookupByAddress(byte[] addr) throws UnknownHostException Lookup the host name corresponding to the raw IP address provided. `addr` argument is in network byte order: the highest order byte of the address is in `addr[0]`. IPv4 address byte array must be 4 bytes long and IPv6 byte array must be 16 bytes long. Parameters addr:byte[] byte array representing a raw IP address Returns:String `String` representing the host name mapping Exceptions UnknownHostException: if no host name is found for the specified IP address IllegalArgumentException: if the length of the provided byte array doesn't correspond to a valid IP address length NullPointerException: if addr is `null`

public String lookupByAddress(byte[] addr) throws UnknownHostException

Lookup the host name corresponding to the raw IP address provided.

addr argument is in network byte order: the highest order byte of the address is in addr[0].

IPv4 address byte array must be 4 bytes long and IPv6 byte array must be 16 bytes long.

Parameters

addr:byte[]: byte array representing a raw IP address

Returns:String

String representing the host name mapping

Exceptions

UnknownHostException:: if no host name is found for the specified IP address
IllegalArgumentException:: if the length of the provided byte array doesn't correspond to a valid IP address length
NullPointerException:: if addr is null

lookupByName back to summary

lookupByName	back to summary
public Stream<InetAddress> lookupByName(String host, InetAddressResolver.LookupPolicy lookupPolicy) throws UnknownHostException Given the name of a host, returns a stream of IP addresses of the requested address family associated with a provided hostname. `host` should be a machine name, such as "`www.example.com`", not a textual representation of its IP address. No validation is performed on the given `host` name: if a textual representation is supplied, the name resolution is likely to fail and `UnknownHostException` may be thrown. The address family type and addresses order are specified by the `LookupPolicy` instance. Lookup operation characteristics could be acquired with `LookupPolicy#characteristics()`. If `InetAddressResolver.LookupPolicy#IPV4` and `InetAddressResolver.LookupPolicy#IPV6` characteristics provided then this method returns addresses of both IPV4 and IPV6 families. Parameters host:String the specified hostname lookupPolicy:InetAddressResolver.LookupPolicy the address lookup policy Returns:Stream<InetAddress> a stream of IP addresses for the requested host Exceptions UnknownHostException: if no IP address for the `host` could be found NullPointerException: if either parameter is `null` See Also `LookupPolicy`

public Stream<InetAddress> lookupByName(String host, InetAddressResolver.LookupPolicy lookupPolicy) throws UnknownHostException

Given the name of a host, returns a stream of IP addresses of the requested address family associated with a provided hostname.

host should be a machine name, such as "www.example.com", not a textual representation of its IP address. No validation is performed on the given host name: if a textual representation is supplied, the name resolution is likely to fail and UnknownHostException may be thrown.

The address family type and addresses order are specified by the LookupPolicy instance. Lookup operation characteristics could be acquired with LookupPolicy#characteristics(). If InetAddressResolver.LookupPolicy#IPV4 and InetAddressResolver.LookupPolicy#IPV6 characteristics provided then this method returns addresses of both IPV4 and IPV6 families.

Parameters

host:String: the specified hostname
lookupPolicy:InetAddressResolver.LookupPolicy: the address lookup policy

Returns:Stream<InetAddress>

a stream of IP addresses for the requested host

Exceptions

UnknownHostException:: if no IP address for the host could be found
NullPointerException:: if either parameter is null

See Also

LookupPolicy

java.net.spi back to summary

public final Class InetAddressResolver.LookupPolicy

Class Inheritance

extends Object

java.lang.Object
java.net.spi.InetAddressResolver.LookupPolicy

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

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

Constructor Summary

Access	Constructor and Description
private	LookupPolicy(int characteristics)

Method Summary

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

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

Field Detail

characteristics	back to summary
private final int characteristics

IPV4	back to summary
public static final int IPV4 Characteristic value signifying if IPv4 addresses need to be queried during lookup. Annotations @Native

IPV4_FIRST	back to summary
public static final int IPV4_FIRST Characteristic value signifying if IPv4 addresses should be returned first by `InetAddressResolver`. Annotations @Native

IPV6	back to summary
public static final int IPV6 Characteristic value signifying if IPv6 addresses need to be queried during lookup. Annotations @Native

IPV6_FIRST	back to summary
public static final int IPV6_FIRST Characteristic value signifying if IPv6 addresses should be returned first by `InetAddressResolver`. Annotations @Native

Constructor Detail

LookupPolicy	back to summary
private LookupPolicy(int characteristics)

Method Detail

characteristics back to summary

characteristics	back to summary
public int characteristics() Returns the set of characteristics of this lookup policy. Returns:int a characteristics value See Also `InetAddressResolver#lookupByName(String, LookupPolicy)`

public int characteristics()

Returns the set of characteristics of this lookup policy.

Returns:int: a characteristics value
See Also: InetAddressResolver#lookupByName(String, LookupPolicy)

of back to summary

of	back to summary
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: `LookupPolicy#IPV4`: to request IPv4 addresses `LookupPolicy#IPV6`: to request IPv6 addresses It is an error if neither `LookupPolicy#IPV4` or `LookupPolicy#IPV6` are set. To request a specific ordering of the results: `LookupPolicy#IPV4_FIRST`: return IPv4 addresses before any IPv6 address `LookupPolicy#IPV6_FIRST`: return IPv6 addresses before any IPv4 address If neither `LookupPolicy#IPV4_FIRST` or `LookupPolicy#IPV6_FIRST` are set it implies "system" order of addresses. It is an error to request both `LookupPolicy#IPV4_FIRST` and `LookupPolicy#IPV6_FIRST`. Parameters characteristics:int a value which represents the set of lookup characteristics Returns:InetAddressResolver.LookupPolicy an instance of `InetAddressResolver.LookupPolicy` Exceptions IllegalArgumentException: if an illegal characteristics bit mask is provided See Also `InetAddressResolver#lookupByName(String, LookupPolicy)`

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:

LookupPolicy#IPV4: to request IPv4 addresses
LookupPolicy#IPV6: to request IPv6 addresses

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

To request a specific ordering of the results:

LookupPolicy#IPV4_FIRST: return IPv4 addresses before any IPv6 address
LookupPolicy#IPV6_FIRST: return IPv6 addresses before any IPv4 address

If neither LookupPolicy#IPV4_FIRST or LookupPolicy#IPV6_FIRST are set it implies "system" order of addresses. It is an error to request both LookupPolicy#IPV4_FIRST and LookupPolicy#IPV6_FIRST.

Parameters

characteristics:int: a value which represents the set of lookup characteristics

Returns:InetAddressResolver.LookupPolicy

an instance of InetAddressResolver.LookupPolicy

Exceptions

IllegalArgumentException:: if an illegal characteristics bit mask is provided

public Interface InetAddressResolver

Nested and Inner Type Summary

Method Summary

Method Detail

public final Class InetAddressResolver.LookupPolicy

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail