InternetAddress abstract interface

abstract interface class InternetAddress

An internet address or a Unix domain address.

This object holds an internet address. If this internet address is the result of a DNS lookup, the address also holds the hostname used to make the lookup. An Internet address combined with a port number represents an endpoint to which a socket can connect or a listening socket can bind.

Constructors

InternetAddress() factory

factory InternetAddress(String address, {InternetAddressType? type})

Creates a new InternetAddress from a numeric address or a file path.

If type is InternetAddressType.IPv4, address must be a numeric IPv4 address (dotted-decimal notation). If type is InternetAddressType.IPv6, address must be a numeric IPv6 address (hexadecimal notation). If type is InternetAddressType.unix, address must be a valid file path. If type is omitted, address must be either a numeric IPv4 or IPv6 address and the type is inferred from the format.

Implementation

external factory InternetAddress(String address, {InternetAddressType? type});

InternetAddress.fromRawAddress() factory

factory InternetAddress.fromRawAddress(
  Uint8List rawAddress, {
  InternetAddressType? type,
})

Creates a new InternetAddress from the provided raw address bytes.

If the type is InternetAddressType.IPv4, the rawAddress must have length 4. If the type is InternetAddressType.IPv6, the rawAddress must have length 16. If the type is InternetAddressType.unix, the rawAddress must be a valid UTF-8 encoded file path.

If type is omitted, the rawAddress must have a length of either 4 or 16, in which case the type defaults to InternetAddressType.IPv4 or InternetAddressType.IPv6 respectively.

Implementation

external factory InternetAddress.fromRawAddress(
  Uint8List rawAddress, {
  InternetAddressType? type,
});

Properties

address no setter

String get address

The numeric address of the host.

For IPv4 addresses this is using the dotted-decimal notation. For IPv6 it is using the hexadecimal representation. For Unix domain addresses, this is a file path.

Implementation

String get address;

hashCode no setter inherited

int get hashCode

The hash code for this object.

A hash code is a single integer which represents the state of the object that affects operator == comparisons.

All objects have hash codes. The default hash code implemented by Object represents only the identity of the object, the same way as the default operator == implementation only considers objects equal if they are identical (see identityHashCode).

If operator == is overridden to use the object state instead, the hash code must also be changed to represent that state, otherwise the object cannot be used in hash based data structures like the default Set and Map implementations.

Hash codes must be the same for objects that are equal to each other according to operator ==. The hash code of an object should only change if the object changes in a way that affects equality. There are no further requirements for the hash codes. They need not be consistent between executions of the same program and there are no distribution guarantees.

Objects that are not equal are allowed to have the same hash code. It is even technically allowed that all instances have the same hash code, but if clashes happen too often, it may reduce the efficiency of hash-based data structures like HashSet or HashMap.

If a subclass overrides hashCode, it should override the operator == operator as well to maintain consistency.

Inherited from Object.

Implementation

external int get hashCode;

host no setter

String get host

The host used to lookup the address.

If there is no host associated with the address this returns the address.

Implementation

String get host;

isLinkLocal no setter

bool get isLinkLocal

Whether the scope of the InternetAddress is a link-local.

Implementation

bool get isLinkLocal;

isLoopback no setter

bool get isLoopback

Whether the InternetAddress is a loopback address.

Implementation

bool get isLoopback;

isMulticast no setter

bool get isMulticast

Whether the scope of the InternetAddress is multicast.

Implementation

bool get isMulticast;

rawAddress no setter

Uint8List get rawAddress

The raw address of this InternetAddress.

For an IP address, the result is either a 4 or 16 byte long list. For a Unix domain address, UTF-8 encoded byte sequences that represents address is returned.

The returned list is a fresh copy, making it possible to change the list without modifying the InternetAddress.

Implementation

Uint8List get rawAddress;

runtimeType no setter inherited

Type get runtimeType

A representation of the runtime type of the object.

Inherited from Object.

Implementation

external Type get runtimeType;

type no setter

InternetAddressType get type

The address family of the InternetAddress.

Implementation

InternetAddressType get type;

Methods

noSuchMethod() inherited

dynamic noSuchMethod(Invocation invocation)

Invoked when a nonexistent method or property is accessed.

A dynamic member invocation can attempt to call a member which doesn't exist on the receiving object. Example:

dynamic object = 1;
object.add(42); // Statically allowed, run-time error

This invalid code will invoke the noSuchMethod method of the integer 1 with an Invocation representing the .add(42) call and arguments (which then throws).

Classes can override noSuchMethod to provide custom behavior for such invalid dynamic invocations.

A class with a non-default noSuchMethod invocation can also omit implementations for members of its interface. Example:

class MockList<T> implements List<T> {
  noSuchMethod(Invocation invocation) {
    log(invocation);
    super.noSuchMethod(invocation); // Will throw.
  }
}
void main() {
  MockList().add(42);
}

This code has no compile-time warnings or errors even though the MockList class has no concrete implementation of any of the List interface methods. Calls to List methods are forwarded to noSuchMethod, so this code will log an invocation similar to Invocation.method(#add, [42]) and then throw.

If a value is returned from noSuchMethod, it becomes the result of the original invocation. If the value is not of a type that can be returned by the original invocation, a type error occurs at the invocation.

The default behavior is to throw a NoSuchMethodError.

Inherited from Object.

Implementation

@pragma("vm:entry-point")
@pragma("wasm:entry-point")
external dynamic noSuchMethod(Invocation invocation);

reverse()

Future<InternetAddress> reverse()

Performs a reverse DNS lookup on this address

Returns a new InternetAddress with the same address, but where the host field set to the result of the lookup.

If this address is Unix domain addresses, no lookup is performed and this address is returned directly.

Implementation

Future<InternetAddress> reverse();

toString() inherited

String toString()

A string representation of this object.

Some classes have a default textual representation, often paired with a static parse function (like int.parse). These classes will provide the textual representation as their string representation.

Other classes have no meaningful textual representation that a program will care about. Such classes will typically override toString to provide useful information when inspecting the object, mainly for debugging or logging.

Inherited from Object.

Implementation

external String toString();

Operators

operator ==() inherited

bool operator ==(Object other)

The equality operator.

The default behavior for all Objects is to return true if and only if this object and other are the same object.

Override this method to specify a different equality relation on a class. The overriding method must still be an equivalence relation. That is, it must be:

• Total: It must return a boolean for all arguments. It should never throw.

• Reflexive: For all objects o, o == o must be true.

• Symmetric: For all objects o1 and o2, o1 == o2 and o2 == o1 must either both be true, or both be false.

• Transitive: For all objects o1, o2, and o3, if o1 == o2 and o2 == o3 are true, then o1 == o3 must be true.

The method should also be consistent over time, so whether two objects are equal should only change if at least one of the objects was modified.

If a subclass overrides the equality operator, it should override the hashCode method as well to maintain consistency.

Inherited from Object.

Implementation

external bool operator ==(Object other);

Static Properties

anyIPv4 no setter

InternetAddress get anyIPv4

IP version 4 any address.

Use this address when listening on the addresses of all adapters using IP version 4 (IPv4).

Implementation

external static InternetAddress get anyIPv4;

anyIPv6 no setter

InternetAddress get anyIPv6

IP version 6 any address.

Use this address when listening on the addresses of all adapters using IP version 6 (IPv6).

Implementation

external static InternetAddress get anyIPv6;

loopbackIPv4 no setter

InternetAddress get loopbackIPv4

IP version 4 loopback address.

Use this address when listening on or connecting to the loopback adapter using IP version 4 (IPv4).

Implementation

external static InternetAddress get loopbackIPv4;

loopbackIPv6 no setter

InternetAddress get loopbackIPv6

IP version 6 loopback address.

Use this address when listening on or connecting to the loopback adapter using IP version 6 (IPv6).

Implementation

external static InternetAddress get loopbackIPv6;

Static Methods

lookup()

Future<List<InternetAddress>> lookup(
  String host, {
  InternetAddressType type = InternetAddressType.any,
})

Looks up the addresses of a host.

If type is InternetAddressType.any, it will lookup both IP version 4 (IPv4) and IP version 6 (IPv6) addresses. If type is either InternetAddressType.IPv4 or InternetAddressType.IPv6 it will only lookup addresses of the specified type. The order of the list can, and most likely will, change over time.

Implementation

external static Future<List<InternetAddress>> lookup(
  String host, {
  InternetAddressType type = InternetAddressType.any,
});

tryParse()

InternetAddress? tryParse(String address)

Attempts to parse address as a numeric address.

Returns null If address is not a numeric IPv4 (dotted-decimal notation) or IPv6 (hexadecimal representation) address.

Implementation

external static InternetAddress? tryParse(String address);