B4J Question how to: BIDIRECTIONAL SOCKET

[paul fredrick]

where can I find examples to create a service that can receive and send json via socket?
Thank you

 

[DonManfred]

This is the english part of the forum. Please write, at least, english here.
You can alternatively post your question in the italian sub-forum.

 

[paul fredrick]

This is the english part of the forum. Please write, at least, english here.
You can alternatively post your question in the italian sub-forum.

modified...

 

[Erel]

Start with this example: https://www.b4x.com/android/forum/t...-asyncstreams-b4xserializator.119011/#content

 

[paul fredrick]

thanks, I have tried the various examples with success, but I would need to get a multiple and simultaneous connection of N clients to 1 server.
it's possible?
how?
thank you

 

[TILogistic]

see: Server B4J.

As it is based on AsyncStreams and it can handle multiple concurrent connections.

[B4X] FTP Server implemented with Socket and AsyncStreams

(Note that the FTP client above is not part of this solution. It only demonstrates how you can use a standard FTP client to communicate with the server.) This is an example of using low level network features to implement a high level protocol. It is an implementation of a standard FTP server...

www.b4x.com

 

[Erel]

Another multiclient socket based example: MJPEG / CCTV Server

 

[LucaMs]

But if you want two-way sockets, wouldn't it be better to use websockets?

 

[Erel]

Regular / low level sockets are also bidirectional.

 

[paul fredrick]

thanks for the replies, but that's not exactly what i'd like to get.
based on Erel's example, https://www.b4x.com/android/forum/t...-asyncstreams-b4xserializator.119011/#content
I have adapted some things to my needs.
1) I declare the PORT - SERVER - CLIENT - STREAM:

Private client1 As Socket
Private client2 As Socket
Public server1 As ServerSocket
Public server2 As ServerSocket
Private astream1 As AsyncStreams
Private astream2 As AsyncStreams
Private const PORT1 As Int = 50001
Private const PORT2 As Int = 50002

etc...
2) I initialize the PORT and put them in listening

server1.Initialize (PORT1, "server1")
ListenForConnections1
server2.Initialize (PORT2, "server2")
ListenForConnections2

etc...
3) I create the SUB

Private Sub ListenForConnections1
Do While working
server1.Listen
Wait For Server1_NewConnection (Successful As Boolean, NewSocket1 As Socket)
If Successful Then
client1 = NewSocket1
astream1.InitializePrefix (client1.InputStream, False, client1.OutputStream, "astream")
connected = True
End If
Loop
End Sub
Private Sub ListenForConnections2
Do While working
server2.Listen
Wait For Server2_NewConnection (Successful As Boolean, NewSocket2 As Socket)
If Successful Then
client2 = NewSocket2
astream2.InitializePrefix (client2.InputStream, False, client2.OutputStream, "astream")
connected = True
End If
Loop
End Sub

etc...
4) I identify the origin in the stream, where nrClient is a data that comes from the client

Public Sub SendData (data () As Byte)
If nrClient = 1 Then
If connected Then astream1.Write (data)
End If
If nrClient = 2 Then
If connected Then astream2.Write (data)
End If
End Sub

5) finally send with SEND_ACTION

everything works...
but if i had 20 clients, i would have to multiply everything
my question is
are there better solutions to achieve the same result?

Thanks again

 

[Erel]

are there better solutions to achieve the same result?

Of course.

See my answer in post #7.

 

[paul fredrick]

Of course.

See my answer in post #7.

i saw it but i can't rebuild it in b4j.

 

[Erel]

A cross platform FTP server: https://www.b4x.com/android/forum/t...d-with-socket-and-asyncstreams.74320/#content

The relevant code is inside the FTPServer library (unzip the b4xlib file).