B4J Question B4J telnet client / socket client

[victormedranop]

Hi, I just finished an socket apps with MySQL backend. to received data from some devices like
GPS and Android phones. But I'm having some troubles when I try to create a client with B4J.

if anyone have a sample client socket TCP.

thanks,

Victor

 

[Erel]

Start with this example: [B4X] Network + AsyncStreams + B4XSerializator

 

[victormedranop]

Hi Erel, try the example. but get estrange chars in front of the data.

Sending DATA �NB3,imei=

I m able to connect and send data but the server refuse because that char

any work around?

victor

 

[ThRuST]

I guess you have to specify the char format in the parameter so look that up.

 

[DonManfred]

Upload a small project which shoes the issue.
I fear that you are using a Textfile which is not UTF8 encoded or maybe it have an BOM.

Without seeing your code it is hard to help

 

[victormedranop]

it's true donManfred. simple code here. Still Learning.

Sub Class_Globals
 Private astream_client As AsyncStreams
 Public String2Send As String
End Sub

Private Sub ConnectToServer(Host As String)
 Log("Trying to connect to: " & Host)
 Dim clienttelnet As Socket
 clienttelnet.Initialize("client")
 clienttelnet.Connect(Host, 12345, 10000)
 Wait For Client_Connected (Successful As Boolean)
 If Successful Then
  Log("Connect Sucesfully")
  astream_client.InitializePrefix(clienttelnet.InputStream, False, clienttelnet.OutputStream, "astream_client")
  SendData(String2Send)
 Else
  Log("Failed to connect: " & LastException)
 End If
End Sub


Public Sub SendData (data As String )
 Log("Sending DATA " & String2Send)
 astream.Write(data.GetBytes("UTF8"))
 astream.Close
End Sub

Private Sub AStream_client_Terminated
 LogError("Closing Client Connection")
End Sub

Private Sub AStream_Client_Error
 LogError("Astream Error")
End Sub

 

[DonManfred]

String2Send

you did not show where does the String come from!?

 

[victormedranop]

sorry

Dim data As String = "POP,imei=356496043991264&rmc=$GPRMC,140223.00,A,1827.50471,N,06954.75904,W,0.041,,140518,,,A*62,AUTO,G00001,,,,9999,M21,36,4017mV,2.07"

 

[DonManfred]

The Text in your error seems to be another

Sending DATA �NB3,imei=

Does not look like the String you posted

Dim data As String = "POP,imei=356496

 

[DonManfred]

Add a log just before sending the String.
Convert the String to HEX and log the HEX Output.... This makes it easier to understand what you are really sending....

 

[victormedranop]

This is the full project.
the idea is receive some info, sabe in MySQL and connect to other server and send the same data received.
I made some server examples but I always receive some trash like this.

�

Thanks.

Victor

 

[victormedranop]

I traced the connection with tcpdump and this is the result.

10:46:55.464525 IP (tos 0x0, ttl 64, id 39028, offset 0, flags [DF], proto TCP (6), length 60)
67.205.187.213.47578 > 148.103.7.40.12345: Flags , cksum 0x9b60 (incorrect -> 0x591c), seq 2543739037, win 29200, options [mss 1460,sackOK,TS val 107542761 ecr 0,nop,wscale 7], length 0
0x0000: 4500 003c 9874 4000 4006 0716 43cd bbd5 E..<.t@[email protected]...
0x0010: 9467 0728 b9da 3039 979e 609d 0000 0000 .g.(..09..`.....
0x0020: a002 7210 9b60 0000 0204 05b4 0402 080a ..r..`..........
0x0030: 0668 f8e9 0000 0000 0103 0307 .h..........
10:46:55.528525 IP (tos 0x0, ttl 64, id 39029, offset 0, flags [DF], proto TCP (6), length 52)
67.205.187.213.47578 > 148.103.7.40.12345: Flags [.], cksum 0x9b58 (incorrect -> 0x368c), seq 2543739038, ack 2845112230, win 229, options [nop,nop,TS val 107542777 ecr 74027], length 0
0x0000: 4500 0034 9875 4000 4006 071d 43cd bbd5 E..4.u@[email protected]...
0x0010: 9467 0728 b9da 3039 979e 609e a994 f7a6 .g.(..09..`.....
0x0020: 8010 00e5 9b58 0000 0101 080a 0668 f8f9 .....X.......h..
0x0030: 0001 212b ..!+

 

[victormedranop]

my mistake. in function

Public Sub SendData (data As String )
 Log("Sending DATA " & String2Send)
 astream.Write(data.GetBytes("UTF8"))
 astream.Close
End Sub

I was using the server astream. just changed to

Public Sub SendData (data As String )
 Log("Sending DATA " & String2Send)
 astream_client.Write(data.GetBytes("UTF8"))
 astream.Close
End Sub

thanks donManfred. always appreciated you help.


Victor

 

[OliverA]

This may just be a typo on this board, but

Public Sub SendData (data As String )
 Log("Sending DATA " & String2Send)
 astream_client.Write(data.GetBytes("UTF8"))
 astream.Close
End Sub

it looks like you are closing the wrong stream (astream instead of astream_client). Unless you meant to close the other stream.

 

[victormedranop]

True. Thanks.

Victor