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How to refresh Bluetooth device name [Scan Cache]?

I am working on an application where I am connecting with the BLE device and sending commands.
One of that commands we have a command for changing the Bluetooth device name.
Communication is working fine, but the problem is when we send the command for changing the name it was working, BLE confirms the input and sends us the output, but when we disconnect and run LE Scan it was showing the same name as the previous, it should show the new name of the device.
If I want to get the latest name of the device I need to open the Bluetooth page manually in the device and scan over there in the scan result it was showing the latest name, when I open the app again which is in the background and its scanning under LE scan function with 10-sec delay, it was showing the new name in the list.
How can I ask Bluetooth manager or system to refresh the cache or refresh data for that Bluetooth device ?.
I don't know it was right to create ticket, but i have created ticket in google issue tracker : https://issuetracker.google.com/issues/233924346
Thanks.

I had the same problem and solved it by reading the new name from the raw scan data. In this way you never have to use device.getName() which returns the old name from the cache. This is Android Java code for the scan callback function.
private ScanCallback newscancallback()
{
ScanCallback scb;
// Device scan callback.
scb = new ScanCallback()
{
#Override
public void onScanResult(int callbackType, ScanResult result)
{
super.onScanResult(callbackType, result);
int n,k,len,getout;
BluetoothDevice dev;
byte[] rec;
StringBuilder nameb;
String name;
dev = result.getDevice();
// do not use dev.getName() which returns cached name
// read current name from raw scan record instead
name = null;
rec = result.getScanRecord().getBytes();
len = rec.length;
nameb = new StringBuilder();
n = 0;
getout = 0;
// search scan record for name
while(n < len-2 && rec[n] != 0 && getout == 0)
{
// rec[n] is length of next item
// rec[n+1] is item type - look for 8 or 9=name
// rec[n+2].. is the name, length rec[n]-1
if(rec[n] > 1 && (rec[n+1] == 8 || rec[n+1] == 9)
{ // found name
for(k = 0 ; k < rec[n]-1 ; ++k)
nameb.append((char)rec[n+2+k]);
name = nameb.toString();
getout = 1;
}
else // go to next item
n += rec[n] + 1;
}
// name is now null or the new name from the scan record
}
#Override
public void onScanFailed(int errcode)
{
}
#Override
public void onBatchScanResults(List<ScanResult> result)
{
}
};
return (scb);
}

As you can see the latest name in the Bluetooth settings of the mobile device, I believe there is no issue with the Bluetooth manager of the system. The issue will be in the scanning function of the code as it is not actually refreshing the scan list yet and it might saved the last known BLE list somewhere in the cache. If you are using third-party library, you might need to check their documentation or codes about how the scan function actually works. There may be like force-refresh option or something in the library. As far as I know, to save the device's battery, there is a delay to actually refresh the scan list.

Zebra RFID API Read Access Operation Code return null

I'm trying to develop a small Application for a Zebra handheld rfid reader and can't find a way to access the MemoryBank of the tag. My reader configuration is as follows:
private void ConfigureReader() {
if (reader.isConnected()) {
TriggerInfo triggerInfo = new TriggerInfo();
triggerInfo.StartTrigger.setTriggerType(START_TRIGGER_TYPE.START_TRIGGER_TYPE_IMMEDIATE);
triggerInfo.StopTrigger.setTriggerType(STOP_TRIGGER_TYPE.STOP_TRIGGER_TYPE_IMMEDIATE);
try {
// receive events from reader
if (eventHandler == null){
eventHandler = new EventHandler();
}
reader.Events.addEventsListener(eventHandler);
// HH event
reader.Events.setHandheldEvent(true);
// tag event with tag data
reader.Events.setTagReadEvent(true);
reader.Events.setAttachTagDataWithReadEvent(true);
// set trigger mode as rfid so scanner beam will not come
reader.Config.setTriggerMode(ENUM_TRIGGER_MODE.RFID_MODE, true);
// set start and stop triggers
reader.Config.setStartTrigger(triggerInfo.StartTrigger);
reader.Config.setStopTrigger(triggerInfo.StopTrigger);
} catch (InvalidUsageException e) {
e.printStackTrace();
} catch (OperationFailureException e) {
e.printStackTrace();
}
}
}
And the eventReadNotify looks like this:
public void eventReadNotify(RfidReadEvents e) {
// Recommended to use new method getReadTagsEx for better performance in case of large tag population
TagData[] myTags = reader.Actions.getReadTags(100);
if (myTags != null) {
for (int index = 0; index < myTags.length; index++) {
Log.d(TAG, "Tag ID " + myTags[index].getTagID());
ACCESS_OPERATION_CODE aoc = myTags[index].getOpCode();
ACCESS_OPERATION_STATUS aos = myTags[index].getOpStatus();
if (aoc == ACCESS_OPERATION_CODE.ACCESS_OPERATION_READ && aos == ACCESS_OPERATION_STATUS.ACCESS_SUCCESS) {
if (myTags[index].getMemoryBankData().length() > 0) {
Log.d(TAG, " Mem Bank Data " + myTags[index].getMemoryBankData());
}
}
}
}
}
When I'm scanning a tag I get the correct TagID but both myTags[index].getOpCode() and myTags[index].getOpStatus() return null values.
I appreciate every suggestion that might lead to a successful scan.
Thanks.

I managed to find a solution for my problem. To perform any Read or Write task with Zebra Handheld Scanners the following two conditions must be satisfied. Look here for reference: How to write to RFID tag using RFIDLibrary by Zebra?
// make sure Inventory is stopped
reader.Actions.Inventory.stop();
// make sure DPO is disabled
reader.Config.setDPOState(DYNAMIC_POWER_OPTIMIZATION.DISABLE);
You have to stop the inventory and make sure to disable dpo in order to get data other than the TagID from a Tag. Unfortunately this isn't mentioned in the docu for Reading RFID Tags.

Bukkit ProtocolLib Nametags

I am trying to change the name above a players entity. I have successfully done this but it has a side effect of changeing the players skin to the default. How can I change the player's nametag without resetting their skin.
Plugin Librarys Used
ProtocolLib
PacketWrapper
Code used to change name
public void changeNameOnHead(Player player, String name) {
PlayerInfoData pid = new
PlayerInfoData(WrappedGameProfile.fromPlayer(player), 1,
EnumWrappers.NativeGameMode.SURVIVAL,
WrappedChatComponent.fromText(player.getName()));
WrapperPlayServerPlayerInfo wpspi = new WrapperPlayServerPlayerInfo();
wpspi.setAction(EnumWrappers.PlayerInfoAction.REMOVE_PLAYER);
wpspi.setData(Collections.singletonList(pid));
for (Player p: Bukkit.getOnlinePlayers()) {
if (p.equals(player)) {
continue;
}
p.hidePlayer(player);
wpspi.sendPacket(p);
}
ProtocolLibrary.getProtocolManager().addPacketListener(
new PacketAdapter(RoleplayEngine.Instance,
PacketType.Play.Server.PLAYER_INFO) {
#Override
public void onPacketSending(PacketEvent event) {
if (event.getPacket().getPlayerInfoAction().read(0) != EnumWrappers.PlayerInfoAction.ADD_PLAYER) {
return;
}
PlayerInfoData pid =
event.getPacket().getPlayerInfoDataLists().read(0).get(0);
if (pid.getProfile().getUUID() !=
player.getUniqueId()) return;
PlayerInfoData newPid = new PlayerInfoData(
pid.getProfile().withName(name),
pid.getPing(),
pid.getGameMode(),
WrappedChatComponent.fromText(name)
);
event.getPacket().getPlayerInfoDataLists().write(0,
Collections.singletonList(newPid));
}
}
);
for (Player p: Bukkit.getOnlinePlayers()) {
if (p.equals(player)) {
continue;
}
p.showPlayer(player);
}
}

You can try to use this library available in github to change the player's name and skin.
Quick example of usage:
PlayerDisplayModifier p = new PublicDisplayModifier(plugin);
p.changeDisplay(myPlayer, "SkinPlayer", "NewName");
This works if your server is 1.8 and lower, not sure if it works on higher versions.
If your server version is higher than 1.8, you can try using NickNamerIntegratedApi, a plugin that also has an API for devs. It's open sourced, so you can probably dig for the piece of code that makes the nick change possible
Lastly, you can also try to use md-5's iTAG, and a good fork of it by ataranlen

I can't detect face with camera2

I can't find information about face detection on preview in android.hardware.Camera2, would anybody help me with a complete example?
I saw some questions with camera2 examples in github but I can't understand them.
I used Camera2 sample from Google: https://github.com/googlesamples/android-Camera2Basic.
I set face recognition mode to FULL.
mPreviewRequestBuilder.set(CaptureRequest.STATISTICS_FACE_DETECT_MODE, CameraMetadata.STATISTICS_FACE_DETECT_MODE_FULL);
Also I checked STATISTICS_INFO_MAX_FACE_COUNT and STATISTICS_INFO_AVAILABLE_FACE_DETECT_MODES:
int max_count = characteristics.get(
CameraCharacteristics.STATISTICS_INFO_MAX_FACE_COUNT);
int modes [] = characteristics.get(
CameraCharacteristics.STATISTICS_INFO_AVAILABLE_FACE_DETECT_MODES);
Output: maxCount : 5 , modes : [0, 2]
My CaptureCallback:
private CameraCaptureSession.CaptureCallback mCaptureCallback = new CameraCaptureSession.CaptureCallback() {
private void process(CaptureResult result) {
Integer mode = result.get(CaptureResult.STATISTICS_FACE_DETECT_MODE);
Face [] faces = result.get(CaptureResult.STATISTICS_FACES);
if(faces != null && mode != null)
Log.e("tag", "faces : " + faces.length + " , mode : " + mode );
}
#Override
public void onCaptureProgressed(CameraCaptureSession session, CaptureRequest request,
CaptureResult partialResult) {
process(partialResult);
}
#Override
public void onCaptureCompleted(CameraCaptureSession session, CaptureRequest request,
TotalCaptureResult result) {
process(result);
} `
Output: faces : 0 , mode : 2
public static final int STATISTICS_FACE_DETECT_MODE_FULL = 2;
Faces length is constantly 0. Looks like it doesn't recognise a face properly or I missed something.
I know approach with FaceDetector. I just wanted to check how it works with new camera2 Face.
I need to detect face on preview of camera2!

I think that you can't use CameraMetadata.STATISTICS_FACE_DETECT_MODE_FULL, because some devices do not support this type of face detection. Please, can you verify if your device support STATISTICS_FACE_DETECT_MODE_FULL?
If the answer is "NO", please try to use STATISTICS_FACE_DETECT_MODE_SIMPLE
Look at this Samsung Example
https://developer.samsung.com/galaxy/camera#techdocs
There is a sample explaining how to use face detection with camera2 API

retrieve required features of a specific app

i'm tring to get all required features of specific app. i wrote this code
mPackageInfo = getPackageManager().getPackageInfo(packageName, 0);
mFeatures = mPackageInfo.reqFeatures;
if(mFeatures != null) {
for(FeatureInfo feature : mFeatures) {
mString.append(feature.name);
}
}
else {
Log.d("test", "error");
}
mFeatures is FeatureInfo[] variable. mString is StringBuffer type variable. in my logcat i see error. why? how can i solve?

Replace 0 in your getPackageInfo() call with PackageManager.GET_CONFIGURATIONS.