java - Kotlin上的Server-Client应用程序出现问题

Question

我有一个简单的客户端服务器应用程序。客户端编写为Android Project，服务器编写为Gradle Kotlin Project。这是客户端代码(写为AsyncTask):

override fun doInBackground(vararg params: Player){
    try {
        clientSocket = Socket(host, port)

        val writer = PrintWriter(clientSocket.getOutputStream(), true)
        writer.write(serializer.toJson(params[0]))
        writer.flush()

        writer.close()
        clientSocket.close()
    }catch(e: Exception){
        Log.e(TAG, e.message)
    }
}

这是服务器代码:

Thread {
        while (true) {
            val client = serverSocket.accept()
            val inputAsString = client.getInputStream().bufferedReader().use { it.readLine() }
            val player = serializer.fromJson<Player>(inputAsString)
            val connection = UserConnection(client, player, Response(ResponseType.SUCCESS, fetchedText, players))
            val thread = Thread(connection)
            thread.apply { isDaemon = true }.start()
        }

    }.start()

和UserConnection类:

class UserConnection(private val connection: Socket, private val player: Player, var response: Response) :
Runnable {

private var connected = true

private val serializer = Gson()

override fun run() {

    if(connection.isClosed){
        connected = false
        println("client of player ${player.userName} is closed!!!")
    }

    while (connected) {
        val writer = PrintWriter(connection.getOutputStream(), true)
        println(serializer.toJson(response))
        writer.write(serializer.toJson(response))
    }
}

不用担心播放器，响应和响应类型。它们只是数据模型，序列化运行良好。

问题是，套接字在接受后始终关闭，并且UserConnection线程未运行，因此我总是看到“播放器$ {user.userName}的客户端已关闭!!!”

P.S.我尝试不关闭客户端上的Socket(关闭OutputStream后会自动关闭)。如果不关闭客户端上的OutputStream，服务器将无法读取数据(刷新也无法正常工作)

Answer 1

问题出在这一行:

val inputAsString = client.getInputStream().bufferedReader().use { it.readLine() }

它从流中读取所有数据并关闭流，同时InputStream关闭，套接字自动关闭。
代替它，我使用这个:

val inputAsString = client.getInputStream().reader().readText()