ConnectivityManager.NetworkCallback
public
static
class
ConnectivityManager.NetworkCallback
extends Object
java.lang.Object | |
↳ | android.net.ConnectivityManager.NetworkCallback |
Base class for NetworkRequest
callbacks. Used for notifications about network
changes. Should be extended by applications wanting notifications.
A NetworkCallback
is registered by calling
ConnectivityManager.requestNetwork(android.net.NetworkRequest, android.net.ConnectivityManager.NetworkCallback)
,
ConnectivityManager.registerNetworkCallback(android.net.NetworkRequest, android.net.ConnectivityManager.NetworkCallback)
,
or ConnectivityManager.registerDefaultNetworkCallback(android.net.ConnectivityManager.NetworkCallback)
. A NetworkCallback
is
unregistered by calling ConnectivityManager.unregisterNetworkCallback(android.net.ConnectivityManager.NetworkCallback)
.
A NetworkCallback
should be registered at most once at any time.
A NetworkCallback
that has been unregistered can be registered again.
Summary
Constants | |
---|---|
int |
FLAG_INCLUDE_LOCATION_INFO
Inclusion of this flag means location-sensitive redaction requests keeping location info. |
Public constructors | |
---|---|
NetworkCallback()
|
|
NetworkCallback(int flags)
|
Public methods | |
---|---|
void
|
onAvailable(Network network)
Called when the framework connects and has declared a new network ready for use. |
void
|
onBlockedStatusChanged(Network network, boolean blocked)
Called when access to the specified network is blocked or unblocked. |
void
|
onCapabilitiesChanged(Network network, NetworkCapabilities networkCapabilities)
Called when the network corresponding to this request changes capabilities but still satisfies the requested criteria. |
void
|
onLinkPropertiesChanged(Network network, LinkProperties linkProperties)
Called when the network corresponding to this request changes |
void
|
onLosing(Network network, int maxMsToLive)
Called when the network is about to be lost, typically because there are no outstanding requests left for it. |
void
|
onLost(Network network)
Called when a network disconnects or otherwise no longer satisfies this request or callback. |
void
|
onUnavailable()
Called if no network is found within the timeout time specified in
|
Inherited methods | |
---|---|
Constants
FLAG_INCLUDE_LOCATION_INFO
public static final int FLAG_INCLUDE_LOCATION_INFO
Inclusion of this flag means location-sensitive redaction requests keeping location info.
Some objects like NetworkCapabilities
may contain location-sensitive information.
Prior to Android 12, this information is always returned to apps holding the appropriate
permission, possibly noting that the app has used location.
In Android 12 and above, by default the sent objects do not contain any location
information, even if the app holds the necessary permissions, and the system does not
take note of location usage by the app. Apps can request that location information is
included, in which case the system will check location permission and the location
toggle state, and take note of location usage by the app if any such information is
returned.
Use this flag to include any location sensitive data in NetworkCapabilities
sent
via onCapabilitiesChanged(android.net.Network, android.net.NetworkCapabilities)
.
These include:
NetworkCapabilities#getTransportInfo()
) like WifiInfo
contain location sensitive information.
NetworkCapabilities#getOwnerUid()
is location
sensitive for wifi suggestor apps (i.e using
WifiNetworkSuggestion
).Note:
NetworkCapabilities
provided via the callback does
not include location sensitive information.
Constant Value: 1 (0x00000001)
Public constructors
NetworkCallback
public NetworkCallback (int flags)
Parameters | |
---|---|
flags |
int : Value is either 0 or a combination of android.net.ConnectivityManager.NetworkCallback.FLAG_NONE, and FLAG_INCLUDE_LOCATION_INFO |
Public methods
onAvailable
public void onAvailable (Network network)
Called when the framework connects and has declared a new network ready for use.
For callbacks registered with ConnectivityManager.registerNetworkCallback(NetworkRequest, PendingIntent)
, multiple networks may
be available at the same time, and onAvailable will be called for each of these as they
appear.
For callbacks registered with ConnectivityManager.requestNetwork(NetworkRequest, PendingIntent)
and
ConnectivityManager.registerDefaultNetworkCallback(NetworkCallback)
, this means the network passed as an argument
is the new best network for this request and is now tracked by this callback ; this
callback will no longer receive method calls about other networks that may have been
passed to this method previously. The previously-best network may have disconnected, or
it may still be around and the newly-best network may simply be better.
Starting with Build.VERSION_CODES.O
, this will always immediately
be followed by a call to onCapabilitiesChanged(android.net.Network, android.net.NetworkCapabilities)
then by a call to onLinkPropertiesChanged(android.net.Network, android.net.LinkProperties)
, and a call
to onBlockedStatusChanged(android.net.Network, boolean)
.
Do NOT call ConnectivityManager.getNetworkCapabilities(android.net.Network)
or
ConnectivityManager.getLinkProperties(android.net.Network)
or other synchronous ConnectivityManager methods in
this callback as this is prone to race conditions (there is no guarantee the objects
returned by these methods will be current). Instead, wait for a call to
onCapabilitiesChanged(android.net.Network, android.net.NetworkCapabilities)
and
onLinkPropertiesChanged(android.net.Network, android.net.LinkProperties)
whose arguments are guaranteed
to be well-ordered with respect to other callbacks.
Parameters | |
---|---|
network |
Network : The Network of the satisfying network.
This value cannot be null . |
onBlockedStatusChanged
public void onBlockedStatusChanged (Network network, boolean blocked)
Called when access to the specified network is blocked or unblocked.
Do NOT call ConnectivityManager.getNetworkCapabilities(android.net.Network)
or
ConnectivityManager.getLinkProperties(android.net.Network)
or other synchronous ConnectivityManager methods in
this callback as this is prone to race conditions : calling these methods while in a
callback may return an outdated or even a null object.
Parameters | |
---|---|
network |
Network : The Network whose blocked status has changed.
This value cannot be null . |
blocked |
boolean : The blocked status of this Network . |
onCapabilitiesChanged
public void onCapabilitiesChanged (Network network, NetworkCapabilities networkCapabilities)
Called when the network corresponding to this request changes capabilities but still satisfies the requested criteria.
Starting with Build.VERSION_CODES.O
this method is guaranteed
to be called immediately after onAvailable(Network)
.
Do NOT call ConnectivityManager.getLinkProperties(android.net.Network)
or other synchronous
ConnectivityManager methods in this callback as this is prone to race conditions :
calling these methods while in a callback may return an outdated or even a null object.
Parameters | |
---|---|
network |
Network : The Network whose capabilities have changed.
This value cannot be null . |
networkCapabilities |
NetworkCapabilities : The new NetworkCapabilities for this
network.
This value cannot be null . |
onLinkPropertiesChanged
public void onLinkPropertiesChanged (Network network, LinkProperties linkProperties)
Called when the network corresponding to this request changes LinkProperties
.
Starting with Build.VERSION_CODES.O
this method is guaranteed
to be called immediately after onAvailable(Network)
.
Do NOT call ConnectivityManager.getNetworkCapabilities(android.net.Network)
or other synchronous
ConnectivityManager methods in this callback as this is prone to race conditions :
calling these methods while in a callback may return an outdated or even a null object.
Parameters | |
---|---|
network |
Network : The Network whose link properties have changed.
This value cannot be null . |
linkProperties |
LinkProperties : The new LinkProperties for this network.
This value cannot be null . |
onLosing
public void onLosing (Network network, int maxMsToLive)
Called when the network is about to be lost, typically because there are no outstanding
requests left for it. This may be paired with a NetworkCallback#onAvailable
call
with the new replacement network for graceful handover. This method is not guaranteed
to be called before NetworkCallback#onLost
is called, for example in case a
network is suddenly disconnected.
Do NOT call ConnectivityManager.getNetworkCapabilities(android.net.Network)
or
ConnectivityManager.getLinkProperties(android.net.Network)
or other synchronous ConnectivityManager methods in
this callback as this is prone to race conditions ; calling these methods while in a
callback may return an outdated or even a null object.
Parameters | |
---|---|
network |
Network : The Network that is about to be lost.
This value cannot be null . |
maxMsToLive |
int : The time in milliseconds the system intends to keep the network
connected for graceful handover; note that the network may still
suffer a hard loss at any time. |
onLost
public void onLost (Network network)
Called when a network disconnects or otherwise no longer satisfies this request or callback.
If the callback was registered with requestNetwork() or registerDefaultNetworkCallback(), it will only be invoked against the last network returned by onAvailable() when that network is lost and no other network satisfies the criteria of the request.
If the callback was registered with registerNetworkCallback() it will be called for each network which no longer satisfies the criteria of the callback.
Do NOT call ConnectivityManager.getNetworkCapabilities(android.net.Network)
or
ConnectivityManager.getLinkProperties(android.net.Network)
or other synchronous ConnectivityManager methods in
this callback as this is prone to race conditions ; calling these methods while in a
callback may return an outdated or even a null object.
Parameters | |
---|---|
network |
Network : The Network lost.
This value cannot be null . |
onUnavailable
public void onUnavailable ()
Called if no network is found within the timeout time specified in
ConnectivityManager.requestNetwork(android.net.NetworkRequest, android.net.ConnectivityManager.NetworkCallback, int)
call or if the
requested network request cannot be fulfilled (whether or not a timeout was
specified). When this callback is invoked the associated
NetworkRequest
will have already been removed and released, as if
ConnectivityManager.unregisterNetworkCallback(android.net.ConnectivityManager.NetworkCallback)
had been called.