B4J Question Raw Socket vs WebSockets

[Jmu5667]

Hello All

I have been educating myself on Web-sockets etc and they are very powerful and easy to implement. We have an up and coming server app to develop and I want to use B4J. The app must be multi-threaded as it is going to receive tracking data from many different GPS devices which will have different GPS protocols. Some of this devices operate in a fire and forget method and some of them require some form of acknowledgement.

I am sure it is possible to develop this server app using B4J but I have not been able to find any server examples that when a connection is created a new thread is created to handle the data exchange. There will be an MS SQL server back-end database so a DB thread pool will be required.

I would also like to know how threads are disposed of in this case.

I have seen other tracking apps that support many different devices and they assign a port number for each type of app. Is it possible to do something similar with B4J.

Many thanks for reading this and I look forward to all suggestions and advice.

Regards

John.

 

[Erel]

I am sure it is possible to develop this server app using B4J but I have not been able to find any server examples that when a connection is created a new thread is created to handle the data exchange.

This is always the case with B4J WebSocket handlers. Each connection is managed by a different thread.

The threads are returned to the threads pool when the connection is closed.

I have seen other tracking apps that support many different devices and they assign a port number for each type of app

You don't need to use different ports. Use different paths instead.

 

[Jmu5667]

Hi Erel

Thanks for the response. I thought with web sockets that the client also must use a web socket, am I wrong in thinking this ? Most devices just use a raw socket,open the port, transmit and close.


Regards

John.

 

[Erel]

I thought with web sockets that the client also must use a web socket, am I wrong in thinking this ?

That's correct.

See this: https://www.b4x.com/android/forum/threads/websocket-client-library.40221/#content

 

[Jmu5667]

How do I handle devices that use raw sockets and not web sockets ?

 

[Erel]

Which type of devices?

 

[Jmu5667]

The likes of this https://www.amazon.co.uk/Tracker-Ve...?ie=UTF8&qid=1481634529&sr=8-1&keywords=tk103

Also here is a link https://www.traccar.org/ to a service that we have used before, but they are unable to modify there system to cope with some specific device from http://2015.twigcom.com/pages/en/twig-products/twig-protector.php and this device requires an acknowledgement. We do a lot of business with this company.

Regards

John.

 

[Erel]

Can it send http requests?

 

[Jmu5667]

No.

 

[Erel]

You need to use ServerSocket to handle those devices. It can run inside the web server, listening on a different port.

I recommend you to learn this example: https://www.b4x.com/android/forum/threads/mjpeg-cctv-server.73792/#content

It shows how you can, quite easily, handle multiple connections with raw sockets.

 

[Jmu5667]

Thank you.