Added in API level 29

Summary: Nested Classes | Constants | Methods | Inherited Methods

DnsResolver

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Kotlin |Java

public final class DnsResolver
extends Object

java.lang.Object
↳	android.net.DnsResolver

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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
interface	DnsResolver.Callback<T> Base interface for answer callbacks
class	DnsResolver.DnsException Class to represent DNS error

Constants
int	CLASS_IN
int	ERROR_PARSE Indicates that there was an error parsing the response the query.
int	ERROR_SYSTEM Indicates that there was an error sending the query.
int	FLAG_EMPTY
int	FLAG_NO_CACHE_LOOKUP
int	FLAG_NO_CACHE_STORE
int	FLAG_NO_RETRY
int	TYPE_A
int	TYPE_AAAA

Public methods
static DnsResolver	getInstance() Get instance for DnsResolver
void	query(Network network, String domain, int flags, Executor executor, CancellationSignal cancellationSignal, Callback<? super List<InetAddress>> callback) 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 style asynchronously.
void	query(Network network, String domain, int nsType, int flags, Executor executor, CancellationSignal cancellationSignal, Callback<? super List<InetAddress>> callback) Send a DNS query with the specified name and query type, get back a set of InetAddresses with rfc6724 sorting style asynchronously.
void	rawQuery(Network network, byte[] query, int flags, Executor executor, CancellationSignal cancellationSignal, Callback<? super byte[]> callback) Send a raw DNS query.
void	rawQuery(Network network, String domain, int nsClass, int nsType, int flags, Executor executor, CancellationSignal cancellationSignal, Callback<? super byte[]> callback) Send a DNS query with the specified name, class and query type.

Inherited methods

From class java.lang.Object Object clone() Creates and returns a copy of this object. boolean equals(Object obj) Indicates whether some other object is "equal to" this one. void finalize() Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. final Class<?> getClass() Returns the runtime class of this Object. int hashCode() Returns a hash code value for the object. final void notify() Wakes up a single thread that is waiting on this object's monitor. final void notifyAll() Wakes up all threads that are waiting on this object's monitor. String toString() Returns a string representation of the object. final void wait(long timeoutMillis, int nanos) Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed. final void wait(long timeoutMillis) Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed. final void wait() Causes the current thread to wait until it is awakened, typically by being notified or interrupted.

Constants

CLASS_IN

Added in API level 29

public static final int CLASS_IN

Constant Value: 1 (0x00000001)

ERROR_PARSE

Added in API level 29

public static final int ERROR_PARSE

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

Constant Value: 0 (0x00000000)

ERROR_SYSTEM

Added in API level 29

public static final int ERROR_SYSTEM

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

Constant Value: 1 (0x00000001)

FLAG_EMPTY

Added in API level 29

public static final int FLAG_EMPTY

Constant Value: 0 (0x00000000)

FLAG_NO_CACHE_LOOKUP

Added in API level 29

public static final int FLAG_NO_CACHE_LOOKUP

Constant Value: 4 (0x00000004)

FLAG_NO_CACHE_STORE

Added in API level 29

public static final int FLAG_NO_CACHE_STORE

Constant Value: 2 (0x00000002)

FLAG_NO_RETRY

Added in API level 29

public static final int FLAG_NO_RETRY

Constant Value: 1 (0x00000001)

TYPE_A

Added in API level 29

public static final int TYPE_A

Constant Value: 1 (0x00000001)

TYPE_AAAA

Added in API level 29

public static final int TYPE_AAAA

Constant Value: 28 (0x0000001c)

Public methods

getInstance

Added in API level 29

public static DnsResolver getInstance ()

Get instance for DnsResolver

Returns
DnsResolver	This value cannot be null.

query

Added in API level 29

public void query (Network network, 
                String domain, 
                int flags, 
                Executor executor, 
                CancellationSignal cancellationSignal, 
                Callback<? super List<InetAddress>> callback)

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 style asynchronously. This method will examine the connection ability on given network, and query IPv4 and IPv6 if connection is available. 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 FLAG_EMPTY, FLAG_NO_RETRY, FLAG_NO_CACHE_STORE, or FLAG_NO_CACHE_LOOKUP
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	Callback: 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

public void query (Network network, 
                String domain, 
                int nsType, 
                int flags, 
                Executor executor, 
                CancellationSignal cancellationSignal, 
                Callback<? super List<InetAddress>> callback)

Send a DNS query with the specified name and query type, get back a set of InetAddresses with rfc6724 sorting style 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 TYPE_A, or TYPE_AAAA
flags	int: flags as a combination of the FLAGS_* constants Value is FLAG_EMPTY, FLAG_NO_RETRY, FLAG_NO_CACHE_STORE, or FLAG_NO_CACHE_LOOKUP
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	Callback: 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

public void rawQuery (Network network, 
                byte[] query, 
                int flags, 
                Executor executor, 
                CancellationSignal cancellationSignal, 
                Callback<? super byte[]> callback)

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	byte: blob message to query This value cannot be null.
flags	int: flags as a combination of the FLAGS_* constants Value is FLAG_EMPTY, FLAG_NO_RETRY, FLAG_NO_CACHE_STORE, or FLAG_NO_CACHE_LOOKUP
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	Callback: 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

public void rawQuery (Network network, 
                String domain, 
                int nsClass, 
                int nsType, 
                int flags, 
                Executor executor, 
                CancellationSignal cancellationSignal, 
                Callback<? super byte[]> callback)

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 CLASS_IN
nsType	int: dns resource record (RR) type as one of the TYPE_* constants Value is TYPE_A, or TYPE_AAAA
flags	int: flags as a combination of the FLAGS_* constants Value is FLAG_EMPTY, FLAG_NO_RETRY, FLAG_NO_CACHE_STORE, or FLAG_NO_CACHE_LOOKUP
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	Callback: a Callback which will be called to notify the caller of the result of dns query. This value cannot be null.