【发布时间】:2017-12-24 21:05:24
【问题描述】:
因此,当我尝试通过 TCP 与我的两台平板电脑和一个支持 Wifi 的外部设备进行通信时,我遇到了一个奇怪的问题。
我会尽量描述这个问题。该系统的工作原理如下(所有通信均通过无线网络进行):
- 设备向平板电脑A发送TCP通信
- tablet A (master) 显示消息并将消息重复到 tablet B (slave) - 这工作正常
- 平板电脑 A 向平板电脑 B 发送另一条消息(操作消息),平板电脑 B 毫无问题地收到该消息
- 当 平板电脑 B 执行操作时,它会向 平板电脑 A 发送 action 消息 - 问题出在这里,消息 确实即使发送,也不会被消耗。如果我移动到另一个
activity并返回到上一个,则消息被消耗
运行 Android 6.0.1 的 Lenovo YT3 平板电脑会出现这种情况
SocketListenerService
private var thread: Thread? = null
private var socketListener: SocketListener? = null
private var broadcastManager: LocalBroadcastManager? = null
val listener = object : SimpleServer.ServerReceivedListener {
override fun onLineReceived(line: String) {
val response = Intent(SOCKET_RESPONSE)
response.putExtra(RESPONSE_MESSAGE, line)
broadcastManager!!.sendBroadcast(response)
}
}
private val incomingServer = SimpleServer(listener)
override fun onCreate() {
super.onCreate()
broadcastManager = LocalBroadcastManager.getInstance(this)
}
override fun onStartCommand(intent: Intent?, flags: Int, startId: Int): Int {
if (intent != null) {
socketListener = SocketListener()
thread = Thread(socketListener)
thread!!.start()
}
return super.onStartCommand(intent, flags, startId)
}
override fun onDestroy() {
super.onDestroy()
socketListener!!.shutDown()
thread!!.interrupt()
incomingServer.closeServer()
}
override fun onBind(intent: Intent): IBinder? {
return null
}
private inner class SocketListener : Runnable {
@Volatile private var done = false
internal fun shutDown() {
done = true
}
override fun run() {
while (!done) {
incomingServer.serve()
}
}
}
companion object {
val SOCKET_RESPONSE = "socket_response"
val RESPONSE_MESSAGE = "response_message"
val port = 9888
}
SimpleServer
interface ServerReceivedListener {
fun onLineReceived(line: String)
}
private var server: ServerSocket? = null
private var client: Socket? = null
private var listener: ServerReceivedListener? = null
init {
try {
server = ServerSocket(SocketListenerService.port)
this.listener = listener
} catch (err: Exception) {
err.printStackTrace()
}
}
fun serve() {
var line: String?
try {
if (!server!!.isClosed) {
client = server?.accept()
val r = BufferedReader(InputStreamReader(client!!.getInputStream(), "UTF-8"))
line = r.readLine()
while (line != null) {
if (line.length >= 4)
listener!!.onLineReceived(line)
else
listener!!.onLineReceived("@")
line = r.readLine()
}
}
} catch (e: IOException) {
if (!e.message!!.contains("Socket closed"))
e.printStackTrace()
}
}
fun closeServer() {
try {
if (client != null)
client!!.close()
server!!.close()
} catch (e: IOException) {
e.printStackTrace()
}
}
BroadcastBeceiver 反过来从 Intent 中获取消息并使用接口将其发送到 activity
我似乎无法理解为什么来自 slave 的通信只有在消费 activity 重新启动时才被 master 消费(?)
【问题讨论】:
标签: android tcp server network-programming kotlin