Added in API level 29

DnsResolver

class DnsResolver
kotlin.Any
   ↳ android.net.DnsResolver

Dns resolver class for asynchronous dns querying Note that if a client sends a query with more than 1 record in the question section but the remote dns server does not support this, it may not respond at all, leading to a timeout.

Summary

Nested classes
abstract

Base interface for answer callbacks

Class to represent DNS error
Constants
static Int

static Int

Indicates that there was an error parsing the response the query.
static Int

Indicates that there was an error sending the query.
static Int

static Int

static Int

static Int

static Int

Indicates that the default wait time should be used for the HTTPS query.
static Int

Indicates that no additional wait should be used for the HTTPS query.
static Int

Indicates that the HTTPS query will be retransmitted until it gets a response, or until it times out.
static Int

static Int

static Int

Public methods
static DnsResolver

Get instance for DnsResolver
static DnsResolver
getInstance(context: Context, looper: Looper?)

Returns a DnsResolver instance.
Unit
query(network: Network?, domain: String, nsType: Int, flags: Int, executor: Executor, cancellationSignal: CancellationSignal?, callback: DnsResolver.Callback<in MutableList<InetAddress!>!>)

Send a DNS query with the specified name and query type, get back a set of InetAddresses with rfc6724 sorting asynchronously.
Unit
query(network: Network?, domain: String, flags: Int, executor: Executor, cancellationSignal: CancellationSignal?, callback: DnsResolver.Callback<in MutableList<InetAddress!>!>)

Send a DNS query with the specified name on a network with both IPv4 and IPv6, get back a set of InetAddresses with rfc6724 sorting asynchronously.
Unit
query(network: Network?, domain: String, flags: Int, executor: Executor, httpsTimeoutMillis: Int, cancellationSignal: CancellationSignal?, callback: DnsResolver.Callback<HttpsEndpoint!>)

Send concurrent A/AAAA/HTTPS DNS queries with the specified name on a network.
Unit
rawQuery(network: Network?, query: ByteArray, flags: Int, executor: Executor, cancellationSignal: CancellationSignal?, callback: DnsResolver.Callback<in ByteArray!>)

Send a raw DNS query.
Unit
rawQuery(network: Network?, domain: String, nsClass: Int, nsType: Int, flags: Int, executor: Executor, cancellationSignal: CancellationSignal?, callback: DnsResolver.Callback<in ByteArray!>)

Send a DNS query with the specified name, class and query type.

Constants

CLASS_IN

Added in API level 29
static val CLASS_IN: Int
 
Value: 1

ERROR_PARSE

Added in API level 29
static val ERROR_PARSE: Int

Indicates that there was an error parsing the response the query. The cause of this error is available via getCause() and is a ParseException.

Value: 0

ERROR_SYSTEM

Added in API level 29
static val ERROR_SYSTEM: Int

Indicates that there was an error sending the query. The cause of this error is available via getCause() and is an ErrnoException.

Value: 1

FLAG_EMPTY

Added in API level 29
static val FLAG_EMPTY: Int
 
Value: 0

FLAG_NO_CACHE_LOOKUP

Added in API level 29
static val FLAG_NO_CACHE_LOOKUP: Int
 
Value: 4

FLAG_NO_CACHE_STORE

Added in API level 29
static val FLAG_NO_CACHE_STORE: Int
 
Value: 2

FLAG_NO_RETRY

Added in API level 29
static val FLAG_NO_RETRY: Int
 
Value: 1

HTTPS_QUERY_WAIT_AUTO

Added in API level 29
static val HTTPS_QUERY_WAIT_AUTO: Int

Indicates that the default wait time should be used for the HTTPS query.

This option balances the extra latency of waiting for the HTTPS record with the latency and security benefits of receiving it.

Value: -1

HTTPS_QUERY_WAIT_NONE

Added in API level 29
static val HTTPS_QUERY_WAIT_NONE: Int

Indicates that no additional wait should be used for the HTTPS query.

This option means the callback will be called immediately as soon as the IP address queries have received a response, regardless of whether the HTTPS query has received a response or not.

This option is not recommended for security or latency because it may result in HTTPS records not being returned even if they exist.

Value: 0

HTTPS_QUERY_WAIT_UNTIL_TIMEOUT

Added in API level 29
static val HTTPS_QUERY_WAIT_UNTIL_TIMEOUT: Int

Indicates that the HTTPS query will be retransmitted until it gets a response, or until it times out.

This option may increase latency if the HTTPS query is dropped by the network.

Value: -2

TYPE_A

Added in API level 29
static val TYPE_A: Int
 
Value: 1

TYPE_AAAA

Added in API level 29
static val TYPE_AAAA: Int
 
Value: 28

TYPE_HTTPS

Added in API level 29
static val TYPE_HTTPS: Int
 
Value: 65

Public methods

getInstance

Added in API level 29
static fun getInstance(): DnsResolver

Deprecated: Use getInstance(Context,Looper) instead.

Get instance for DnsResolver

Return
DnsResolver This value cannot be null.

getInstance

Added in API level 29
static fun getInstance(
    context: Context, 
    looper: Looper?
): DnsResolver

Returns a DnsResolver instance.

Parameters
context Context: used for internal interactions with other system services.
This value cannot be null.
looper Looper?: Looper for monitoring incoming replies to DNS queries. If null, then uses the value returned by Looper.getMainLooper().
Return
DnsResolver This value cannot be null.

query

Added in API level 29
fun query(
    network: Network?, 
    domain: String, 
    nsType: Int, 
    flags: Int, 
    executor: Executor, 
    cancellationSignal: CancellationSignal?, 
    callback: DnsResolver.Callback<in MutableList<InetAddress!>!>
): Unit

Send a DNS query with the specified name and query type, get back a set of InetAddresses with rfc6724 sorting asynchronously. The answer will be provided asynchronously through the provided Callback.

Parameters
network Network?: Network specifying which network to query on. null for query on default network.
domain String: domain name to query.
This value cannot be null.
nsType Int: dns resource record (RR) type as one of the TYPE_* constants.
Value is one of the following:
flags Int: flags as a combination of the FLAGS_* constants.
Value is one of the following:
executor Executor: The Executor that the callback should be executed on.
This value cannot be null.
Callback and listener events are dispatched through this Executor, providing an easy way to control which thread is used. To dispatch events through the main thread of your application, you can use Context.getMainExecutor(). Otherwise, provide an Executor that dispatches to an appropriate thread.
cancellationSignal CancellationSignal?: used by the caller to signal if the query should be cancelled. May be null.
callback DnsResolver.Callback<in MutableList<InetAddress!>!>: a Callback which will be called to notify the caller of the result of dns query.
This value cannot be null.

query

Added in API level 29
fun query(
    network: Network?, 
    domain: String, 
    flags: Int, 
    executor: Executor, 
    cancellationSignal: CancellationSignal?, 
    callback: DnsResolver.Callback<in MutableList<InetAddress!>!>
): Unit

Send a DNS query with the specified name on a network with both IPv4 and IPv6, get back a set of InetAddresses with rfc6724 sorting asynchronously. This method will examine the connection ability on given network, and query IPv4 and IPv6 if connection is available. This method will send A queries if the specified Network provides IPv4 connectivity, and AAAA queries if it provides IPv6 connectivity. If at least one query succeeded with valid answer, rcode will be 0 The answer will be provided asynchronously through the provided Callback.

Parameters
network Network?: Network specifying which network to query on. null for query on default network.
domain String: domain name to query.
This value cannot be null.
flags Int: flags as a combination of the FLAGS_* constants.
Value is one of the following:
executor Executor: The Executor that the callback should be executed on.
This value cannot be null.
Callback and listener events are dispatched through this Executor, providing an easy way to control which thread is used. To dispatch events through the main thread of your application, you can use Context.getMainExecutor(). Otherwise, provide an Executor that dispatches to an appropriate thread.
cancellationSignal CancellationSignal?: used by the caller to signal if the query should be cancelled. May be null.
callback DnsResolver.Callback<in MutableList<InetAddress!>!>: a Callback which will be called to notify the caller of the result of dns query.
This value cannot be null.

query

Added in API level 29
fun query(
    network: Network?, 
    domain: String, 
    flags: Int, 
    executor: Executor, 
    httpsTimeoutMillis: Int, 
    cancellationSignal: CancellationSignal?, 
    callback: DnsResolver.Callback<HttpsEndpoint!>
): Unit

Send concurrent A/AAAA/HTTPS DNS queries with the specified name on a network. The answer to all queries will be provided asynchronously through the provided callback Callback, which provides a HttpsEndpoint.

Parameters
network Network?: Network specifying which network to query on. null for query on default network.
domain String: domain name to query.
This value cannot be null.
flags Int: flags as a combination of the FLAGS_* constants.
Value is one of the following:
executor Executor: The Executor that the callback should be executed on.
This value cannot be null.
Callback and listener events are dispatched through this Executor, providing an easy way to control which thread is used. To dispatch events through the main thread of your application, you can use Context.getMainExecutor(). Otherwise, provide an Executor that dispatches to an appropriate thread.
httpsTimeoutMillis Int: the timeout in milliseconds to wait for the HTTPS query to complete after the A/AAAA queries have already completed. May be set to HTTPS_QUERY_WAIT_NONE to disable any additional wait, HTTPS_QUERY_WAIT_AUTO to use the default wait time, HTTPS_QUERY_WAIT_UNTIL_TIMEOUT to wait for the HTTPS query to complete, or a specific value in milliseconds.
cancellationSignal CancellationSignal?: used by the caller to signal if all the queries should be cancelled. May be null.
callback DnsResolver.Callback<HttpsEndpoint!>: a Callback which will be called to notify the caller of the results of the A/AAAA/HTTPS DNS queries. Will return a ERROR_PARSE if any of the DNS records cannot be parsed, and should be treated as a resolution failure.
This value cannot be null.

rawQuery

Added in API level 29
fun rawQuery(
    network: Network?, 
    query: ByteArray, 
    flags: Int, 
    executor: Executor, 
    cancellationSignal: CancellationSignal?, 
    callback: DnsResolver.Callback<in ByteArray!>
): Unit

Send a raw DNS query. The answer will be provided asynchronously through the provided Callback.

Parameters
network Network?: Network specifying which network to query on. null for query on default network.
query ByteArray: blob message to query.
This value cannot be null.
flags Int: flags as a combination of the FLAGS_* constants.
Value is one of the following:
executor Executor: The Executor that the callback should be executed on.
This value cannot be null.
Callback and listener events are dispatched through this Executor, providing an easy way to control which thread is used. To dispatch events through the main thread of your application, you can use Context.getMainExecutor(). Otherwise, provide an Executor that dispatches to an appropriate thread.
cancellationSignal CancellationSignal?: used by the caller to signal if the query should be cancelled. May be null.
callback DnsResolver.Callback<in ByteArray!>: a Callback which will be called to notify the caller of the result of dns query.
This value cannot be null.

rawQuery

Added in API level 29
fun rawQuery(
    network: Network?, 
    domain: String, 
    nsClass: Int, 
    nsType: Int, 
    flags: Int, 
    executor: Executor, 
    cancellationSignal: CancellationSignal?, 
    callback: DnsResolver.Callback<in ByteArray!>
): Unit

Send a DNS query with the specified name, class and query type. The answer will be provided asynchronously through the provided Callback.

Parameters
network Network?: Network specifying which network to query on. null for query on default network.
domain String: domain name to query.
This value cannot be null.
nsClass Int: dns class as one of the CLASS_* constants.
Value is one of the following:
nsType Int: dns resource record (RR) type as one of the TYPE_* constants.
Value is one of the following:
flags Int: flags as a combination of the FLAGS_* constants.
Value is one of the following:
executor Executor: The Executor that the callback should be executed on.
This value cannot be null.
Callback and listener events are dispatched through this Executor, providing an easy way to control which thread is used. To dispatch events through the main thread of your application, you can use Context.getMainExecutor(). Otherwise, provide an Executor that dispatches to an appropriate thread.
cancellationSignal CancellationSignal?: used by the caller to signal if the query should be cancelled. May be null.
callback DnsResolver.Callback<in ByteArray!>: a Callback which will be called to notify the caller of the result of dns query.
This value cannot be null.