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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 |
Constants | |
|---|---|
int |
ERROR_HARDWARE_ERROR
The hardware returned an error. |
int |
ERROR_INSUFFICIENT_RESOURCES
The limitation of resource is reached. |
int |
ERROR_INVALID_INTERVAL
The packet transmission interval is invalid (e.g., too short). |
int |
ERROR_INVALID_IP_ADDRESS
The specified IP addresses are invalid. |
int |
ERROR_INVALID_LENGTH
The packet length is invalid (e.g., too long). |
int |
ERROR_INVALID_NETWORK
The specified |
int |
ERROR_INVALID_PORT
The requested port is invalid. |
int |
ERROR_INVALID_SOCKET
The target socket is invalid. |
int |
ERROR_SOCKET_NOT_IDLE
The target socket is not idle. |
int |
ERROR_UNSUPPORTED
The device does not support this request. |
Public methods | |
|---|---|
final
void
|
close()
Deactivate this |
final
void
|
start(int intervalSec)
Request that keepalive be started with the given |
final
void
|
stop()
Requests that keepalive be stopped. |
Inherited methods | |
|---|---|
Constants
ERROR_HARDWARE_ERROR
public static final int ERROR_HARDWARE_ERROR
The hardware returned an error.
Constant Value: -31 (0xffffffe1)
ERROR_INSUFFICIENT_RESOURCES
public static final int ERROR_INSUFFICIENT_RESOURCES
The limitation of resource is reached.
Constant Value: -32 (0xffffffe0)
ERROR_INVALID_INTERVAL
public static final int ERROR_INVALID_INTERVAL
The packet transmission interval is invalid (e.g., too short).
Constant Value: -24 (0xffffffe8)
ERROR_INVALID_IP_ADDRESS
public static final int ERROR_INVALID_IP_ADDRESS
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
public static final int ERROR_INVALID_LENGTH
The packet length is invalid (e.g., too long).
Constant Value: -23 (0xffffffe9)
ERROR_INVALID_NETWORK
public static final int ERROR_INVALID_NETWORK
The specified Network is not connected.
Constant Value: -20 (0xffffffec)
ERROR_INVALID_PORT
public static final int ERROR_INVALID_PORT
The requested port is invalid.
Constant Value: -22 (0xffffffea)
ERROR_INVALID_SOCKET
public static final int ERROR_INVALID_SOCKET
The target socket is invalid.
Constant Value: -25 (0xffffffe7)
ERROR_SOCKET_NOT_IDLE
public static final int ERROR_SOCKET_NOT_IDLE
The target socket is not idle.
Constant Value: -26 (0xffffffe6)
ERROR_UNSUPPORTED
public static final int ERROR_UNSUPPORTED
The device does not support this request.
Constant Value: -30 (0xffffffe2)
Public methods
close
public final void close ()
Deactivate this SocketKeepalive and free allocated resources. The instance won't be
usable again if close() is called.
start
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 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
probably going down anyway. If the caller cares regardless, it can use a custom
Executor to catch the RemoteException.
| 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
public final void stop ()
Requests that keepalive be stopped. The application must wait for Callback#onStopped
before using the object. See SocketKeepalive.