I have socket programming and for every client i'm creating new threads and using application with multithreads as in below.

fun ClientHandler() {
        try {
            var count = 0
            var serverSocket = ServerSocket(5000)

            while (true) {
                val socket: Socket = serverSocket!!.accept()
                count  
                socket.reuseAddress = true
                _log("${socket.remoteSocketAddress} Client Connected. Connected client count is $count")
                Thread(ServerThread(socket)).start() //Here i'm creating Threads. 
            }
        } catch (e: ConnectException) {
            _logEx("UnExpected connection error", e)
        } catch (ex: IOException) {
            _logEx("ClientHandler", ex)
        } catch (e: Exception) {
            _logEx("ServerSocketHandler ", e)
        }

}

internal inner class ServerThread(socket: Socket) : Runnable  {
    private val client: Socket = socket
    private val reader: Scanner = Scanner(client.getInputStream())
    private val writer = PrintStream(client.getOutputStream())
    private var receiveString: String = ""
    override fun run() {
        try {
            while(reader.hasNextLine()){
                receiveString = reader.nextLine() ?: ""
                _log("Message received: "   receiveString)
                if (receiveString != null && receiveString != "") {
                    checkMessage(receiveString, writer,client)
                }
            }
        } catch (ex: Exception) {
            _log("Cannot read the message. Please try again")
            //_log(ex.localizedMessage)
            val spReq = Error()
            spReq.sendErrorMsg(writer, "Cannot read the message. Please try again",client)
        }
    }
}

Update I added ServerThread code part too.

How to follow them and get their statuses?

CodePudding user response：

You can keep track of the threads and their state by having a Map for further reference

fun ClientHandler() {
    try {
        var count = 0
        val serverSocket = ServerSocket(5000)

        while (true) {
            val socket: Socket = serverSocket.accept()
            count  
            socket.reuseAddress = true
            threads["thread name here"] = ServerThread(socket)
        }
    } catch (e: ConnectException) {
        e.printStackTrace()
    } catch (e: IOException) {
        e.printStackTrace()
    } catch (e: Exception) {
        e.printStackTrace()
    }
}

fun stopServerThread(threadName: String) {
    threads[threadName]?.interrupt()
}

internal inner class ServerThread(private val client: Socket) : Thread()  {
    private val reader = Scanner(client.getInputStream())
    private val writer = PrintStream(client.getOutputStream())
    private var receiveString: String = ""
    
    init {
        start()
    }
    
    override fun run() {
        try {
            while(reader.hasNextLine()){
                if (isInterrupted) {
                    break
                }
                receiveString = reader.nextLine() ?: ""
                if (receiveString != "") {
                    checkMessage(receiveString, writer, client)
                }
            }
        } catch (ex: Exception) {
            _log("Cannot read the message. Please try again")
            //_log(ex.localizedMessage)
            val spReq = Error()
            spReq.sendErrorMsg(writer, "Cannot read the message. Please try again",client)
        }
    }
}