SocketKeepalive

Kotlin |Java

abstract class SocketKeepalive : AutoCloseable

kotlin.Any
↳	android.net.SocketKeepalive

Allows applications to request that the system periodically send specific packets on their behalf, using hardware offload to save battery power. To request that the system send keepalives, call one of the methods that return a SocketKeepalive object, such as ConnectivityManager.createSocketKeepalive, passing in a non-null callback. If the SocketKeepalive is successfully started, the callback's onStarted method will be called. If an error occurs, onError will be called, specifying one of the ERROR_* constants in this class. To stop an existing keepalive, call SocketKeepalive.stop. The system will call SocketKeepalive.Callback.onStopped if the operation was successful or SocketKeepalive.Callback.onError if an error occurred. For cellular, the device MUST support at least 1 keepalive slot. For WiFi, the device SHOULD support keepalive offload. If it does not, it MUST reply with SocketKeepalive.Callback.onError with ERROR_UNSUPPORTED to any keepalive offload request. If it does, it MUST support at least 3 concurrent keepalive slots.

Summary

Nested classes
open	`Callback` The callback which app can use to learn the status changes of `SocketKeepalive`.

Constants
static Int	`ERROR_HARDWARE_ERROR` There was a hardware error.
static Int	`ERROR_INSUFFICIENT_RESOURCES` Resources are insufficient (e.g. all hardware slots are in use).
static Int	`ERROR_INVALID_INTERVAL` The interval is invalid (e.g. too short).
static Int	`ERROR_INVALID_IP_ADDRESS` The invalid IP addresses.
static Int	`ERROR_INVALID_LENGTH` The length is invalid (e.g. too long).
static Int	`ERROR_INVALID_NETWORK` The invalid network.
static Int	`ERROR_INVALID_PORT` The port is invalid.
static Int	`ERROR_INVALID_SOCKET` The socket is invalid.
static Int	`ERROR_SOCKET_NOT_IDLE` The socket is not idle.
static Int	`ERROR_UNSUPPORTED` The request is unsupported.

Public methods
Unit	`close()` Deactivate this `SocketKeepalive` and free allocated resources.
Unit	`start(intervalSec: Int)` Request that keepalive be started with the given `intervalSec`.
Unit	`stop()` Requests that keepalive be stopped.

Constants

ERROR_HARDWARE_ERROR

Added in API level 29

static val ERROR_HARDWARE_ERROR: Int

There was a hardware error.

Value: -31

ERROR_INSUFFICIENT_RESOURCES

Added in API level 29

static val ERROR_INSUFFICIENT_RESOURCES: Int

Resources are insufficient (e.g. all hardware slots are in use).

Value: -32

ERROR_INVALID_INTERVAL

Added in API level 29

static val ERROR_INVALID_INTERVAL: Int

The interval is invalid (e.g. too short).

Value: -24

ERROR_INVALID_IP_ADDRESS

Added in API level 29

static val ERROR_INVALID_IP_ADDRESS: Int

The invalid IP addresses. Indicates the specified IP addresses are invalid. For example, the specified source IP address is not configured on the specified Network.

Value: -21

ERROR_INVALID_LENGTH

Added in API level 29

static val ERROR_INVALID_LENGTH: Int

The length is invalid (e.g. too long).

Value: -23

ERROR_INVALID_NETWORK

Added in API level 29

static val ERROR_INVALID_NETWORK: Int

The invalid network. It indicates the specified Network is not connected.

Value: -20

ERROR_INVALID_PORT

Added in API level 29

static val ERROR_INVALID_PORT: Int

The port is invalid.

Value: -22

ERROR_INVALID_SOCKET

Added in API level 29

static val ERROR_INVALID_SOCKET: Int

The socket is invalid.

Value: -25

ERROR_SOCKET_NOT_IDLE

Added in API level 29

static val ERROR_SOCKET_NOT_IDLE: Int

The socket is not idle.

Value: -26

ERROR_UNSUPPORTED

Added in API level 29

static val ERROR_UNSUPPORTED: Int

The request is unsupported.

Value: -30

Public methods

close

Added in API level 29

fun close(): Unit

Deactivate this SocketKeepalive and free allocated resources. The instance won't be usable again if close() is called.

Exceptions
`java.lang.Exception`	if this resource cannot be closed

start

Added in API level 29

fun start(intervalSec: Int): Unit

Request that keepalive be started with the given intervalSec. See SocketKeepalive. If the remote binder dies, or the binder call throws an exception when invoking start or stop of the SocketKeepalive, a RuntimeException caused by a RemoteException will be thrown into the Executor. This is typically not important to catch because the remote party is the system, so if it is not in shape to communicate through binder the system is going down anyway. If the caller still cares, it can use a custom Executor to catch the RuntimeException.

Parameters
`intervalSec`	Int: The target interval in seconds between keepalive packet transmissions. The interval should be between 10 seconds and 3600 seconds, otherwise `ERROR_INVALID_INTERVAL` will be returned. Value is between MIN_INTERVAL_SEC and MAX_INTERVAL_SEC inclusive

stop

Added in API level 29

fun stop(): Unit

Requests that keepalive be stopped. The application must wait for Callback.onStopped before using the object. See SocketKeepalive.