SocketKeepalive

public abstract class SocketKeepalive
extends Object implements AutoCloseable

java.lang.Object
   ↳ 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

class SocketKeepalive.Callback

The callback which app can use to learn the status changes of SocketKeepalive. 

Constants

int ERROR_HARDWARE_ERROR

There was a hardware error.

int ERROR_INSUFFICIENT_RESOURCES

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

int ERROR_INVALID_INTERVAL

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

int ERROR_INVALID_IP_ADDRESS

The invalid IP addresses.

int ERROR_INVALID_LENGTH

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

int ERROR_INVALID_NETWORK

The invalid network.

int ERROR_INVALID_PORT

The port is invalid.

int ERROR_INVALID_SOCKET

The socket is invalid.

int ERROR_SOCKET_NOT_IDLE

The socket is not idle.

int ERROR_UNSUPPORTED

The request is unsupported.

Public methods

final void close()

Deactivate this SocketKeepalive and free allocated resources.

final void start(int intervalSec)

Request that keepalive be started with the given intervalSec.

final void stop()

Requests that keepalive be stopped.

Inherited methods

Constants

ERROR_HARDWARE_ERROR

Added in API level 29 
public static final int ERROR_HARDWARE_ERROR

There was a hardware error.

Constant Value: -31 (0xffffffe1)

ERROR_INSUFFICIENT_RESOURCES

Added in API level 29 
public static final int ERROR_INSUFFICIENT_RESOURCES

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

Constant Value: -32 (0xffffffe0)

ERROR_INVALID_INTERVAL

Added in API level 29 
public static final int ERROR_INVALID_INTERVAL

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

Constant Value: -24 (0xffffffe8)

ERROR_INVALID_IP_ADDRESS

Added in API level 29 
public static final int ERROR_INVALID_IP_ADDRESS

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.

Constant Value: -21 (0xffffffeb)

ERROR_INVALID_LENGTH

Added in API level 29 
public static final int ERROR_INVALID_LENGTH

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

Constant Value: -23 (0xffffffe9)

ERROR_INVALID_NETWORK

Added in API level 29 
public static final int ERROR_INVALID_NETWORK

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

Constant Value: -20 (0xffffffec)

ERROR_INVALID_PORT

Added in API level 29 
public static final int ERROR_INVALID_PORT

The port is invalid.

Constant Value: -22 (0xffffffea)

ERROR_INVALID_SOCKET

Added in API level 29 
public static final int ERROR_INVALID_SOCKET

The socket is invalid.

Constant Value: -25 (0xffffffe7)

ERROR_SOCKET_NOT_IDLE

Added in API level 29 
public static final int ERROR_SOCKET_NOT_IDLE

The socket is not idle.

Constant Value: -26 (0xffffffe6)

ERROR_UNSUPPORTED

Added in API level 29 
public static final int ERROR_UNSUPPORTED

The request is unsupported.

Constant Value: -30 (0xffffffe2)

Public methods

close

Added in API level 29 
public final void close ()

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

start

Added in API level 29 
public final void start (int intervalSec)

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 
public final void stop ()

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