I am trying to read all the records stored in a glucometer using rxAndroidBle library. According to several resources that I have found the process consist of three main steps after pairing/bonding and connecting to the device:
Setup indications in the Record Access Control Point characteristic (RACP)
Setup notifications on the Glucose measurement characteristic
Write on the RACP characteristic two bytes 0x01, 0x01.
Then the notifications should flow if there are any records.
Now, this flow has worked fine some times in an LG G5 with android 7.0, but on other phones that I have access to it just won't work. It will throw a gruesome GATT_INTERNAL_ERROR (status 129), which is kind of ambiguous. I found this article which describes kind of what I may be facing.
My concern is that this works but it may be firmware related, which is weird because I've seen it work flawlessly on other application that connects to the glucometer without issue in any device.
Here's what how my test code for this seems like right now:
fun loadRecords(rxBleDevice: RxBleDevice){
...
...
rxBleDevice.establishConnection(false)
.flatMap { rxBleConnection: RxBleConnection ->
rxBleConnection.setupIndication(racpUUID)
.flatMapSingle {
Single.just(rxBleConnection)
}
}
.flatMap { rxBleConnection ->
writeAndReadOnNotification(racpUUID,
glucoseUUID,
byteArrayOf(0x01, 0x01),
false,
rxBleConnection)
}
.subscribe(
{ it:ByteArray ->
decodeReading(it)
},Logger::logException)
}
private fun writeAndReadOnNotification(writeTo: UUID, readOn: UUID,
bytes: ByteArray,
isIndication: Boolean,
rxBleConnection:RxBleConnection)
: Observable<ByteArray> {
val notifObservable = if (isIndication)
rxBleConnection.setupIndication(readOn)
else
rxBleConnection.setupNotification(readOn)
return notifObservable.flatMap { notificationObservable ->
Observable.combineLatest(
notificationObservable,
rxBleConnection.writeCharacteristic(writeTo, bytes).toObservable(),
BiFunction { readBytes: ByteArray, writeBytes: ByteArray -> readBytes })
}
}
and here's what the log looks like for that piece of code:
18:28:58.058 D/BluetoothGatt: connect() - device: E0:7D:EA:FF:38:AB, auto: false
18:28:58.058 D/BluetoothGatt: registerApp()
18:28:58.058 D/BluetoothGatt: registerApp() - UUID=cca42db0-a88f-4b1c-acd0-f7fbe7be536d
18:28:58.065 D/BluetoothGatt: onClientRegistered() - status=0 clientIf=7
18:28:58.518 D/BluetoothGatt: onClientConnectionState() - status=0 clientIf=7 device=E0:7D:EA:FF:38:AB
18:28:58.527 D/BluetoothGatt: discoverServices() - device: E0:7D:EA:FF:38:AB
18:28:58.532 D/BluetoothGatt: onSearchComplete() = Device=E0:7D:EA:FF:38:AB Status=0
18:28:58.873 D/BluetoothGatt: setCharacteristicNotification() - uuid: 00002a52-0000-1000-8000-00805f9b34fb enable: true
18:28:58.965 D/BluetoothGatt: setCharacteristicNotification() - uuid: 00002a18-0000-1000-8000-00805f9b34fb enable: true
18:28:59.057 D/BluetoothGatt: setCharacteristicNotification() - uuid: 00002a18-0000-1000-8000-00805f9b34fb enable: false
18:28:59.061 D/BluetoothGatt: setCharacteristicNotification() - uuid: 00002a52-0000-1000-8000-00805f9b34fb enable: false
18:28:59.066 E/None: com.polidea.rxandroidble2.exceptions.BleGattCharacteristicException: GATT exception from MAC='XX:XX:XX:XX:XX:XX', status 129 (GATT_INTERNAL_ERROR), type BleGattOperation{description='CHARACTERISTIC_WRITE'}. (Look up status 0x81 here https://android.googlesource.com/platform/external/bluetooth/bluedroid/+/android-5.1.0_r1/stack/include/gatt_api.h)
at com.polidea.rxandroidble2.internal.connection.RxBleGattCallback.propagateErrorIfOccurred(RxBleGattCallback.java:243)
at com.polidea.rxandroidble2.internal.connection.RxBleGattCallback.access$800(RxBleGattCallback.java:35)
at com.polidea.rxandroidble2.internal.connection.RxBleGattCallback$2.onCharacteristicWrite(RxBleGattCallback.java:125)
at android.bluetooth.BluetoothGatt$1$7.run(BluetoothGatt.java:438)
at android.bluetooth.BluetoothGatt.runOrQueueCallback(BluetoothGatt.java:770)
at android.bluetooth.BluetoothGatt.access$200(BluetoothGatt.java:39)
at android.bluetooth.BluetoothGatt$1.onCharacteristicWrite(BluetoothGatt.java:433)
at android.bluetooth.IBluetoothGattCallback$Stub.onTransact(IBluetoothGattCallback.java:137)
at android.os.Binder.execTransact(Binder.java:731)
18:28:59.067 D/BluetoothManager: getConnectionState()
18:28:59.067 D/BluetoothManager: getConnectedDevices
18:28:59.074 D/BluetoothGatt: cancelOpen() - device: E0:7D:EA:FF:38:AB
18:28:59.080 D/BluetoothGatt: onClientConnectionState() - status=0 clientIf=7 device=E0:7D:EA:FF:38:AB
18:28:59.083 D/BluetoothGatt: close()
18:28:59.084 D/BluetoothGatt: unregisterApp() - mClientIf=7
18:28:59.507 V/FA: Inactivity, disconnecting from the service
Did I missed something in my code? Why does it work on some phones?
I managed to solve this myself. Looking into the logs I posted earlier I saw that both the indications and the notifications were being disabled right after setting them up, so I made a deep exploration into the library to see, why it was doing so. I turns out that you should not set indications before setting up notifications in whatever characteristic (even though they are two different characteristics). So the main steps to read this should be in this order:
Set up Glucose characteristic notifications and keep observing.
Set up indications on the RACP.
Write 0x01, 0x01 into the RACP.
Profit
Also I found this note in the library code:
/*
*NOTE: due to stateful nature of characteristics if one will setupIndication() before setupNotification()
* the notification will not be set up and will emit an BleCharacteristicNotificationOfOtherTypeAlreadySetException
*/
which led me to move the notification part before the indication part.
Here is what it looks like right now:
fun loadRecords(rxBleDevice: RxBleDevice){
...
//Do stuff
...
rxBleDevice.establishConnection(false)
.flatMap { rxBleConnection: RxBleConnection ->
rxBleConnection.setupNotification(glucoseUUID,
NotificationSetupMode.QUICK_SETUP)
.flatMapSingle {
Single.just(Pair(it, rxBleConnection))
}
}
.flatMap { (observable, rxBleConnection) ->
writeAndReadOnNotification(racpUUID,
racpUUID,
byteArrayOf(0x01, 0x01),
true,
rxBleConnection).subscribe()
observable
}
.subscribe(
{
decodeReading(it)
},Logger::logException)
}
I know it looks ugly and it needs polishing.
Related
I want to use workMager to do some work every 15min,at the same time I want to stop workManger when I clicked on the button "StopThread" below is my Code:
val workManager = WorkManager.getInstance(applicationContext)
val workRequest = PeriodicWorkRequest.Builder(
RandomNumberGeneratorWorker::class.java,
15,
TimeUnit.MINUTES
).addTag("API_Worker")
.build()
binding.buttonThreadStarter.setOnClickListener {
workManager.enqueue(workRequest)
}
binding.buttonStopthread.setOnClickListener {
workManager.cancelAllWorkByTag("API_Worker")
}
And this is the RandomNumberGeneratorWorker
class RandomNumberGeneratorWorker(
context: Context,
params: WorkerParameters
) :
Worker(context, params) {
private val MIN = 0
private val MAX = 100
private var mRandomNumber = 0
override fun doWork(): Result {
Log.d("worker_info","Job Started")
startRandomNumberGenerator();
return Result.success();
}
override fun onStopped() {
super.onStopped()
Log.i("worker_info", "Worker has been cancelled")
}
private fun startRandomNumberGenerator() {
Log.d("worker_info","startRandomNumberGenerator triggered")
var i = 0
while (i < 100 && !isStopped) {
try {
Thread.sleep(1000)
mRandomNumber = (Math.random() * (MAX - MIN + 1)).toInt() + MIN
Log.i(
"worker_info",
"Thread id: " + Thread.currentThread().id + ", Random Number: " + mRandomNumber
)
i++
} catch (e: InterruptedException) {
Log.i("worker_info", "Thread Interrupted")
}
}
}
}
The issue that I'm facing is when I stopped the workManger it didn't work again when I clicked on buttonThreadStarter
I did a little research and I found that I can start-stop-start..etc workManger with the code below :
val workRequest = OneTimeWorkRequest.from(RandomNumberGeneratorWorker::class.java)
binding.buttonThreadStarter.setOnClickListener {
workManager.beginUniqueWork("WorkerName",ExistingWorkPolicy.REPLACE,workRequest)
}
binding.buttonStopthread.setOnClickListener {
workManager.cancelAllWork()
}
but as you can see it's working when I used OneTimeWorkRequest and with that, I can't repeat the work every 15 mins , Any suggestion in how to resolve this issue
WorkManager is not designed for periodic works with exact timing. In reality, the works "are not even periodic".
As you can see here from the logs:
https://developer.android.com/topic/libraries/architecture/workmanager/how-to/debugging#use-alb-shell0dumpsys-jobscheduler
WorkManager delegates to the JobScheduler. JS jobs work in a way that you have a number of explicit(you set them) and implicit(set by the system) constraints and after all of them are satisfied - the job starts.
When you have a period there is an extra constraint - TIMING_DELAY. So if your 15min pass - this doesn't mean in no way that the job will be executed. There might be, and be sure that there will be other constraints. That is the case because WM is designed for resource optimization and it will ensure that the work will finish at some point, even on device restart. But it is not designed to be exact. It is quite the opposite.
And after all the constraints are satisfied - it might take a day, the job is no longer needed and a new job is created with again your 15min constraint - TIMING_DELAY. And the process starts again.
Also - when you say "doesn't trigger" - please, check why. Try to check the debug output from the JS and see if there is work at all. If there is - check what constraints are not satisfied.
But long story short - "every 15min" is not something for WorkManager. Normally you should use AlaramManager for exact timing, but with such a short interval you should try to consider using a Service.
Also, it is dangerous to call: cancelAllWork(). You might break the code of some library in your app. You should better use tags and cancel by tag.
I am getting "Unexpected end of stream" while using Retrofit (2.9.0) with OkHttp3 (4.9.1)
Retrofit configuration:
interface ApiServiceInterface {
companion object Factory{
fun create(): ApiServiceInterface {
val interceptor = HttpLoggingInterceptor()
interceptor.level = HttpLoggingInterceptor.Level.BODY
val client = OkHttpClient.Builder()
.connectTimeout(30, TimeUnit.SECONDS)
.writeTimeout(30, TimeUnit.SECONDS)
.readTimeout(30,TimeUnit.SECONDS)
.addInterceptor(Interceptor { chain ->
chain.request().newBuilder()
.addHeader("Connection", "close")
.addHeader("Accept-Encoding", "identity")
.build()
.let(chain::proceed)
})
.retryOnConnectionFailure(true)
.connectionPool(ConnectionPool(0, 5, TimeUnit.MINUTES))
.protocols(listOf(Protocol.HTTP_1_1))
.build()
val gson = GsonBuilder().setLenient().create()
val retrofit = Retrofit.Builder()
.addCallAdapterFactory(CoroutineCallAdapterFactory())
.addConverterFactory(GsonConverterFactory.create(gson))
.baseUrl("http://***.***.***.***:****")
.client(client)
.build()
return retrofit.create(ApiServiceInterface::class.java)
}
}
#Headers("Content-type: application/json", "Connection: close", "Accept-Encoding: identity")
#POST("/")
fun requestAsync(#Body data: JsonObject): Deferred<Response>
}
So far I have found out the following:
This issue only occurs for me while using Android Studio emulators running from Windows series OS (7, 10, 11) - this was reproduced on 2 different laptops from different networks.
If running Android Studio emulators under OS X the issue won't reproduce in 100% cases.
ARC/Postman clients never has any issues completing same requests to my backend.
On running from Windows Android Studio emulators this issue reproduces in about 10-50% requests, other requests work without problem.
The identical requests can result in this error or complete sucessfully.
Responses which take about 11 sec to complete can result in success, while responses which take about 100 msec to complete can result in this error.
Commenting off .client(client) from retrofit configuration eliminates this issue, but I loose the opportunity to use interceptors and other OkHttp functionality.
Adding headers (Connection: close, Accept-Encoding: identity) does not solve issue.
Turning retryOnConnectionFailure on or off has no impact on issue as well.
Changing HttpLoggingInterceptor level or removing it completely does not solve issue.
Server-side configuration:
const http = require('http');
const server = http.createServer((req, res) => {
const callback = function(code, request, data) {
let result = responser(code, request, data);
res.writeHead(200, {
'Content-Type' : 'x-application/json',
'Connection': 'close',
'Content-Length': Buffer.byteLength(result)
});
res.end(result);
};
...
}
server.listen(process.env.PORT, process.env.HOSTNAME, () => {
console.log(`Server is running`);
});
So, based on 1,2,3 - this is unlikely server-side issue.
Based on 4, 5, 6 - it is not malformed request related or execution time related issue.
Guessing from 7 - this issue roots lay in OkHttp rather than Retrofit itself.
I have read almost half of stackoverflow is search of resolution, like:
unexpected end of stream retrofit
Retrofit OkHttp unexpected end of stream on Connection error
and also discussion at OkHttp on Github:
https://github.com/square/okhttp/issues/3682
https://github.com/square/okhttp/issues/3715
But nothing helped so far.
Any idea what might be causing the problem?
Update
I've got more info on situation.
First, I changed headers on backend to not to pass Content-Length and pass Transfer-Encoding : identity instead. I don't know why, but Postman gives an error if theese headers are present both, saying it is not right.
res.writeHead(200, {
'Content-Type' : 'x-application/json',
'Connection': 'close',
'Transfer-Encoding': 'identity'
});
After that I started to receive another error on Windows hosted Android Studio emulators (with equal ratio of fail / success to "Unexpected end of stream")
2021-12-09 14:58:19.696 401-401/? D/P2P-> FRG DEBUG:: java.io.EOFException: End of input at line 1 column 1807 path $.meta
at com.google.gson.stream.JsonReader.nextNonWhitespace(JsonReader.java:1397)
at com.google.gson.stream.JsonReader.doPeek(JsonReader.java:483)
at com.google.gson.stream.JsonReader.hasNext(JsonReader.java:415)
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.read(ReflectiveTypeAdapterFactory.java:216)
at retrofit2.converter.gson.GsonResponseBodyConverter.convert(GsonResponseBodyConverter.java:40)
at retrofit2.converter.gson.GsonResponseBodyConverter.convert(GsonResponseBodyConverter.java:27)
at retrofit2.OkHttpCall.parseResponse(OkHttpCall.java:243)
at retrofit2.OkHttpCall$1.onResponse(OkHttpCall.java:153)
at okhttp3.internal.connection.RealCall$AsyncCall.run(RealCall.kt:519)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1167)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:641)
at java.lang.Thread.run(Thread.java:764)
Spending a lot of time debugging this issue I have found that this exception was generated by JsonReader.java in method nextNonWhitespace where it try to to get colons, double quotes and curly or square braces to compose json object from decoded as char array buffer.
This buffer itself is received in fillBuffer method of the same module and it has length limit of 1024 elements. In my case the backend response is longer that this value (1807 chars), so while JsonReader.java parses my response as json object it do this in 2 iterations.
Each iteration it fills the buffer here:
int total;
while ((total = in.read(buffer, limit, buffer.length - limit)) != -1) {
limit += total;
// if this is the first read, consume an optional byte order mark (BOM) if it exists
if (lineNumber == 0 && lineStart == 0 && limit > 0 && buffer[0] == '\ufeff') {
pos++;
lineStart++;
minimum++;
}
if (limit >= minimum) {
return true;
}
}
the read method is called on ResponseBody.kt class from okhttp3
#Throws(IOException::class)
override fun read(cbuf: CharArray, off: Int, len: Int): Int {
if (closed) throw IOException("Stream closed")
val finalDelegate = delegate ?: InputStreamReader(
source.inputStream(),
source.readBomAsCharset(charset)).also {
delegate = it
}
return finalDelegate.read(cbuf, off, len)
}
The main problem is:
At first iteration all goes well, ResponseBody.kt "reads" first 1024 chars and gives them to JsonReader.java where it composes a part of response object.
When second iteration comes ResponseBody.kt "reads" the last part of response and fills with it the start of char buffer, so char buffer now contains as its first elements the tail of response, and after that - all elements which was left there after firts iteration.
The main problem is that it im most cases (about 80%) looses last char from response, in about 10% in looses 2 last chars from response and in about 10% it reads all chars. Here is shots:
It must contains 783 chars to complete json, but as shown at line 1290 it receives only 782.
Looking at buffer itself
the char at 782 index (783 in order) must be second curly brace that closes json root, but instead of it there are leftovers from first iteration started. This results in exception mentioned above.
Now if we look at situation where requests finished successfully:
With the same request it occasionly returns valid number of chars: 783
And the buffer itself is:
Now the second brace is present where it must be.
In this case request will be successfull.
The same response ending from Postman:
The Postman success rate in parsing response is 100%, the same is true for OS X hosted android studio emulators and real devices I've used.
Update 2
It seems full buffer obtained in RealBufferedSource.kt:
internal inline fun RealBufferedSource.commonSelect(options: Options): Int {
check(!closed) { "closed" }
while (true) {
val index = buffer.selectPrefix(options, selectTruncated = true)
when (index) {
-1 -> {
return -1
}
-2 -> {
// We need to grow the buffer. Do that, then try it all again.
if (source.read(buffer, Segment.SIZE.toLong()) == -1L) return -1
}
else -> {
// We matched a full byte string: consume it and return it.
val selectedSize = options.byteStrings[index].size
buffer.skip(selectedSize.toLong())
return index
}
}
}
}
and here it is already missing last char:
Update 3
Found this unsolved question which is exactly the same behavior:
Retrofit Json data truncated
Also comment from Android Studio emulators issues tracker:
https://issuetracker.google.com/issues/119027639#comment9
OK, It took some time, but I've found what was going wrong and how to workaround that.
When Android Studio's emulators running in Windows series OS (checked for 7 & 10) receive json-typed reply from server with retrofit it can with various probability loose 1 or 2 last symbols of the body when it is decoded to string, this symbols contain closing curly brackets and so such body could not be parsed to object by gson converter which results in throwing exception.
The idea of workaround I found is to add an interceptor to retrofit which would check the decoded to string body if its last symbols match those of valid json response and add them if they are missed.
interface ApiServiceInterface {
companion object Factory{
fun create(): ApiServiceInterface {
val interceptor = HttpLoggingInterceptor()
interceptor.level = HttpLoggingInterceptor.Level.BODY
val stringInterceptor = Interceptor { chain: Interceptor.Chain ->
val request = chain.request()
val response = chain.proceed(request)
val source = response.body()?.source()
source?.request(Long.MAX_VALUE)
val buffer = source?.buffer()
var responseString = buffer?.clone()?.readString(Charset.forName("UTF-8"))
if (responseString != null && responseString.length > 2) {
val lastTwo = responseString.takeLast(2)
if (lastTwo != "}}") {
val lastOne = responseString.takeLast(1)
responseString = if (lastOne != "}") {
"$responseString}}"
} else {
"$responseString}"
}
}
}
val contentType = response.body()?.contentType()
val body = ResponseBody.create(contentType, responseString ?: "")
return#Interceptor response.newBuilder().body(body).build()
}
val client = OkHttpClient.Builder()
.connectTimeout(30, TimeUnit.SECONDS)
.writeTimeout(30, TimeUnit.SECONDS)
.readTimeout(30,TimeUnit.SECONDS)
.addInterceptor(interceptor)
.addInterceptor(stringInterceptor)
.retryOnConnectionFailure(true)
.connectionPool(ConnectionPool(0, 5, TimeUnit.MINUTES))
.protocols(listOf(Protocol.HTTP_1_1))
.build()
val gson = GsonBuilder().create()
val retrofit = Retrofit.Builder()
.addCallAdapterFactory(CoroutineCallAdapterFactory())
.addConverterFactory(GsonConverterFactory.create(gson))
.addConverterFactory(ScalarsConverterFactory.create())
.baseUrl("http://3.124.6.203:5000")
.client(client)
.build()
return retrofit.create(ApiServiceInterface::class.java)
}
}
#Headers("Content-type: application/json", "Connection: close", "Accept-Encoding: identity")
#POST("/")
fun requestAsync(#Body data: JsonObject): Deferred<Response>
}
After this changes the issue didn't occure.
When I try again in Spring Cloud Stream Reactive, a situation that I don't understand arises, so I ask a question.
In case of sending String type data per second, after processing in s-c-stream Function, I intentionally caused RuntimeException according to conditions.
#Bean
fun test(): Function<Flux<String>, Flux<String>?> = Function{ input ->
input.map { sellerId ->
if(sellerId == "I-ZICGO")
throw RuntimeException("intentional")
else
log.info("do normal: {}", sellerId)
sellerId
}.retryWhen(Retry.from { companion ->
companion.map { rs ->
if (rs.totalRetries() < 3) { // retrying 3 times
log.info("retry!!!: {}", rs.totalRetries())
rs.totalRetries()
}
else
throw Exceptions.propagate(rs.failure())
}
})
}
However, the result of running the above logic is:
2021-02-25 16:14:29.319 INFO 36211 --- [container-0-C-1] o.s.c.s.m.DirectWithAttributesChannel : Channel 'consumer.processingSellerItem-in-0' has 0 subscriber(s).
2021-02-25 16:14:29.322 INFO 36211 --- [container-0-C-1] k.c.m.c.service.impl.ItemServiceImpl : retry!!!: 0
2021-02-25 16:14:29.322 INFO 36211 --- [container-0-C-1] o.s.c.s.m.DirectWithAttributesChannel : Channel 'consumer.processingSellerItem-in-0' has 1 subscriber(s).
Retry is processed only once.
Should I change from reactive to imperative to fix this?
In short, yes. The retry settings are meaningless for reactive functions. You can see a more details explanation on the similar SO question here
I am trying to get Core Motion data from an Apple Watch 3 (WatchOS 5.1) but although the DeviceMotion is available (isDeviceMotionAvailable property is true), the handler is never triggered. I get the following message in the console right after parsing super.willActivate():
[Gyro] Manually set gyro-interrupt-calibration to 800
I am using the following function to get Device Motion updates:
func startQueuedUpdates() {
if motion.isDeviceMotionAvailable {
self.motion.deviceMotionUpdateInterval = 1.0 / 100.0
self.motion.showsDeviceMovementDisplay = true
self.motion.startDeviceMotionUpdates(using: .xMagneticNorthZVertical, to: self.queue, withHandler:{
(data, error) in
// Make sure the data is valid before accessing it.
if let validData = data {
print(String(validData.userAcceleration.x))
}
})
}
}
In the InterfaceController I have declared
let motion = CMMotionManager()
let queue : OperationQueue = OperationQueue.main
Has anyone met this message before and managed to resolve it?
Note: I have checked the isGyroAvailable property and it is false.
The trick here is to match the startDeviceMotionUpdates(using: CMAttitudeReferenceFrame parameter to your device's capabilities. If it has no magnetometer, it cannot relate to magnetic north, and even if it has a magnetometer, it cannot relate to true north unless it knows where you are (i.e. has latitude & longitude). If it hasn't got the capabilities to comply with the parameter you select, the update will be called, but the data will be nil.
If you start it up with the minimum .xArbitraryZVertical you will get updates from the accelerometer, but you won't get a meaningful heading, just a relative one, through the CMDeviceMotion.attitude property ...
if motion.isDeviceMotionAvailable {
print("Motion available")
print(motion.isGyroAvailable ? "Gyro available" : "Gyro NOT available")
print(motion.isAccelerometerAvailable ? "Accel available" : "Accel NOT available")
print(motion.isMagnetometerAvailable ? "Mag available" : "Mag NOT available")
motion.deviceMotionUpdateInterval = 1.0 / 60.0
motion.showsDeviceMovementDisplay = true
motion.startDeviceMotionUpdates(using: .xArbitraryZVertical) // *******
// Configure a timer to fetch the motion data.
self.timer = Timer.scheduledTimer(withTimeInterval: 1, repeats: true) { _ in
if let data = self.motion.deviceMotion {
print(data.attitude.yaw)
}
}
}
I've a Corda application that using M14 to build and run corda to run a TwoPartyProtocol where either parties can exchange data to reach a data validity consensus. I've followed Corda flow cookbook to build a flow.
Also, after reading the docs from several different corda milestones I've understood that M14 no longer needs flowSessions as mentioned in the release notes which also eliminates need to register services.
My TwoPartyFlow with inner FlowLogics:
class TwoPartyFlow{
#InitiatingFlow
#StartableByRPC
open class Requestor(val price: Long,
val otherParty: Party) : FlowLogic<SignedTransaction>(){
#Suspendable
override fun call(): SignedTransaction {
val notary = serviceHub.networkMapCache.notaryNodes.single().notaryIdentity
send(otherParty, price)
/*Some code to generate SignedTransaction*/
}
}
#InitiatedBy(Requestor::class)
open class Responder(val requestingParty : Party) : FlowLogic<SignedTransaction>(){
#Suspendable
override fun call(): SignedTransaction {
val request = receive<Long>(requestor).unwrap { price -> price }
println(request)
/*Some code to generate SignedTransaction*/
}
}
}
But, running the above using startTrackedFlow from Api causes the above error:
Party CN=Other,O=Other,L=NY,C=US rejected session request: com.testapp.flow.TwoPartyFlow$Requestor has not been registered
I had hard time finding the reason from corda docs or logs since Two Party flow implementations have changed among several Milestones of corda. Can someone help me understand the problem here.
My API Call:
#GET
#Path("start-flow")
fun requestOffering(#QueryParam(value = "price") price: String) : Response{
val price : Long = 10L
/*Code to get otherParty details*/
val otherPartyHostAndPort = HostAndPort.fromString("localhost:10031")
val client = CordaRPCClient(otherPartyHostAndPort)
val services : CordaRPCOps = client.start("user1","test").proxy
val otherParty: Party = services.nodeIdentity().legalIdentity
val (status, message) = try {
val flowHandle = services.startTrackedFlow(::Requestor, price, otherParty)
val result = flowHandle.use { it.returnValue.getOrThrow() }
// Return the response.
Response.Status.CREATED to "Transaction id ${result.id} committed to ledger.\n"
} catch (e: Exception) {
Response.Status.BAD_REQUEST to e.message
}
return Response.status(status).entity(message).build()
}
My Gradle deployNodes task:
task deployNodes(type: net.corda.plugins.Cordform, dependsOn: ['build']) {
directory "./build/nodes"
networkMap "CN=Controller,O=R3,OU=corda,L=London,C=UK"
node {
name "CN=Controller,O=R3,OU=corda,L=London,C=UK"
advertisedServices = ["corda.notary.validating"]
p2pPort 10021
rpcPort 10022
cordapps = []
}
node {
name "CN=Subject,O=Subject,L=NY,C=US"
advertisedServices = []
p2pPort 10027
rpcPort 10028
webPort 10029
cordapps = []
rpcUsers = [[ user: "user1", "password": "test", "permissions": []]]
}
node {
name "CN=Other,O=Other,L=NY,C=US"
advertisedServices = []
p2pPort 10030
rpcPort 10031
webPort 10032
cordapps = []
rpcUsers = [[ user: "user1", "password": "test", "permissions": []]]
}
There appears to be a couple of problems with the code you posted:
The annotation should be #StartableByRPC, not #StartableNByRPC
The price passed to startTrackedFlow should be a long, not an int
However, even after fixing these issues, I couldn't replicate your error. Can you apply these fixes, do a clean re-deploy of your nodes (gradlew clean deployNodes), and see whether the error changes?
You shouldn't be connecting to the other node via RPC. RPC is how a node's owner speaks to their node. In the real world, you wouldn't have the other node's RPC credentials, and couldn't log into the node in this way.
Instead, you should use your own node's RPC client to retrieve the counterparty's identity:
val otherParty = services.partyFromX500Name("CN=Other,O=Other,L=NY,C=US")!!
See an M14 example here: https://github.com/corda/cordapp-example/blob/release-M14/kotlin-source/src/main/kotlin/com/example/api/ExampleApi.kt.