Page Summary
-
You can query the current state of a fence by calling
FenceClient.queryFences()with the fence key. -
The response to
queryFences()provides aFenceStateMapwhich contains theFenceStatefor each queried fence. -
FenceStateobjects allow you to retrieve the current state, previous state, and last update time of a fence.
To query for the current state of a fence, call FenceClient.queryFences()
and pass the fence key for the fence to query.
The following example calls FenceClient.queryFences()
to get a FenceStateMap
,
and then uses the FenceStateMap
to return a FenceState
value to show the current state, previous state, and the time when the fence was
last updated:
protected
void
queryFence
(
final
String
fenceKey
)
{
Awareness
.
getFenceClient
(
this
)
.
queryFences
(
FenceQueryRequest
.
forFences
(
Arrays
.
asList
(
fenceKey
)))
.
addOnSuccessListener
(
new
OnSuccessListener<FenceQueryResponse>
()
{
@Override
public
void
onSuccess
(
FenceQueryResponse
response
)
{
FenceStateMap
map
=
response
.
getFenceStateMap
();
for
(
String
fenceKey
:
map
.
getFenceKeys
())
{
FenceState
fenceState
=
map
.
getFenceState
(
fenceKey
);
Log
.
i
(
TAG
,
"Fence "
+
fenceKey
+
": "
+
fenceState
.
getCurrentState
()
+
", was="
+
fenceState
.
getPreviousState
()
+
", lastUpdateTime="
+
DATE_FORMAT
.
format
(
new
Date
(
fenceState
.
getLastFenceUpdateTimeMillis
())));
}
}
}
)
.
addOnFailureListener
(
new
OnFailureListener
()
{
@Override
public
void
onFailure
(
@NonNull
Exception
e
)
{
Log
.
e
(
TAG
,
"Could not query fence: "
+
fenceKey
);
return
;
}
}
);
}
