B4J Question Non_UI application Handler response

[walterf25]

Hi all, i am working on a personal project where I have a B4J Non-UI app running on a google cloud Virtual Machine, the app receives requests with a TokenID and message parameters which then are sent to the firebase messaging API, this works just fine, but i am having a hard time understanding how to send a response back to the client after the call has been made to the fcm.googleapis.com.

Below is my code:

Sub Handle(req As ServletRequest, resp As ServletResponse)
    Dim start As Long = DateTime.Now
    resp.ContentType = "text/html;charset=utf-8"
    response = resp
    Dim messageto As String = req.GetParameter("messageto")
    Select messageto
        Case "Chofer"
            
        Case "Owner"
        SendMessageToOwnerDevice(req.GetParameter("fcmtoken"), req.GetParameter("data"))
        Case "Cliente"
            
    End Select

    Log($"took: ${DateTime.Now - start}ms"$)
    resp.Write("Notification Successful") ''I don't even get this response on the client side.
    StartMessageLoop 'we need this here, for the wait for   
End Sub

Private Sub SendMessageToOwnerDevice(FCMToken As String, datamessage As String)
    Dim Job1 As HttpJob
    Job1.Initialize("SendMessageOwner", Me)
  
    DateTime.DateFormat="dd.MM.yyyy"
    Dim DatumZeit As String
    DatumZeit=DateTime.Date(DateTime.Now)
    DatumZeit=DatumZeit & " " & DateTime.Time(DateTime.Now)
  
  
    Dim m As Map = CreateMap("to": $"${FCMToken}"$)
    Dim data As Map = CreateMap("data": datamessage)
    m.Put("data", data)
    m.Put("content_available", True)
    Dim jg As JSONGenerator
    jg.Initialize(m)
    Job1.Tag=jg
    Log(jg.ToString)
    Job1.PostString("https://fcm.googleapis.com/fcm/send", jg.ToString)
    Job1.GetRequest.SetContentType("application/json;charset=UTF-8")
    Job1.GetRequest.SetHeader("Authorization", "key=" & Main.API_KEY)
End Sub

Sub JobDone(Job As HttpJob)
    If Job.Success Then
        Log("response: " & Job.GetString) '''I see this being logged and according to the logs it returns a successful response.
        response.ContentType = "application/json;charset=utf-8"   
        response.Write(Job.GetString) '''I never receive this response either on the client side
    Else
        '''response.SendError(500, Job.ErrorMessage)
        Log("failed to connect to server: " & Job.ErrorMessage)
    End If
    Job.Release
    StartMessageLoop
End Sub

Does anyone with more experience with this have any idea why that is, on the client side I get the following error:

ResponseError. Reason: java.net.SocketTimeoutException: timeout, Response:
error: java.net.SocketTimeoutException: timeout

Any suggestions guys?

Thanks,
Walter

 

[alwaysbusy]

The StartMessageLoop at the end of the JobDone() method should be a StopMessageLoop I should think.

This is a snippet I use to make some API call (note that I pass the resp variable instead of making it a global variable, not sure if it matters):

Sub Handle(req As ServletRequest, resp As ServletResponse)
    resp.ContentType = "application/json"  
  
    Select Case req.Method
        Case "GET"
            If req.RequestURI.Length + 1 <= "/v1/admin/monitor/".Length Then
                ABMShared.SendError(resp, 404, "Invalid call")
                Return
            End If
            Dim PostType As String = req.RequestURI.SubString("/v1/admin/monitor/".Length)
            Select Case PostType
                Case "latest"
                    RunAPI(resp)
                    StartMessageLoop '<--- start the loop
                Case Else
                    ABMShared.SendError(resp, 404, "Invalid call")
                    Return
            End Select
...

Sub RunAPI(resp As ServletResponse)
    Dim j As HttpJob
    j.Initialize("", Me)
    j.Download(Main.MonitorUrl & "/monitor/latest")
    j.GetRequest.SetHeader("api_key", "eyJhbGciOiJIUzUx...")
    Wait For (j) JobDone(j As HttpJob)
    If j.Success Then
        'Log("Success")
        Dim body As TextReader
        body.Initialize(j.GetInputStream)
        resp.Write(body.ReadAll)
    Else
        resp.Status = j.Response.StatusCode
        resp.Write(j.Response.ErrorResponse)      
    End If
    j.Release
    StopMessageLoop '<--- stop the loop
End Sub

Alwaysbusy

 

[walterf25]

The StartMessageLoop at the end of the JobDone() method should be a StopMessageLoop I should think.

This is a snippet I use to make some API call (note that I pass the resp veriable instead of making it a global variable, not sure if it matters):

Sub Handle(req As ServletRequest, resp As ServletResponse)
    resp.ContentType = "application/json"  
  
    Select Case req.Method
        Case "GET"
            If req.RequestURI.Length + 1 <= "/v1/admin/monitor/".Length Then
                ABMShared.SendError(resp, 404, "Invalid call")
                Return
            End If
            Dim PostType As String = req.RequestURI.SubString("/v1/admin/monitor/".Length)
            Select Case PostType
                Case "latest"
                    RunAPI(resp)
                    StartMessageLoop '<--- start the loop
                Case Else
                    ABMShared.SendError(resp, 404, "Invalid call")
                    Return
            End Select
...

Sub RunAPI(resp As ServletResponse)
    Dim j As HttpJob
    j.Initialize("", Me)
    j.Download(Main.MonitorUrl & "/monitor/latest")
    j.GetRequest.SetHeader("api_key", "eyJhbGciOiJIUzUx...")
    Wait For (j) JobDone(j As HttpJob)
    If j.Success Then
        'Log("Success")
        Dim body As TextReader
        body.Initialize(j.GetInputStream)
        resp.Write(body.ReadAll)
    Else
        resp.Status = j.Response.StatusCode
        resp.Write(j.Response.ErrorResponse)      
    End If
    j.Release
    StopMessageLoop '<--- stop the loop
End Sub

Alwaysbusy

Weird, i could have sworn i had already tried that before, it is working now, thanks for hint.

Walter

 

[Erel]

1. Wait For in servlets: https://www.b4x.com/android/forum/t...t-for-sleep-in-server-handlers.81833/#content
2. Making OkHttpUtils2 thread safe: https://www.b4x.com/android/forum/threads/server-jokhttputils2-server-version.124350/#content