Android okhttp3中发送websocket消息，并通过mockwebserver将一个安卓设备模拟成服务器接发消息

websocket 提供了客户端和服务端的长链接，允许客户端和服务端双向发送消息
okhttp 提供了使用websocket 相关接口议。同时为方便单元测试，又提供了mockwebserver可以把一个安卓客户端作为服务端接受消息。

websocket使用

权限

<uses-permission android:name="android.permission.INTERNET" />

app的build.gradle引入okhttp3库

implementation 'com.squareup.okhttp3:okhttp:5.0.0-alpha.11'

创建监听

inner class MyWebSocketListener :WebSocketListener(){override fun onOpen(webSocket: WebSocket, response: Response) {println("WebSocketListener onOpen 连接到服务器 ")}override open fun onMessage(webSocket: WebSocket, text: String) {println("WebSocketListener onMessage 收到消息 ")}override open fun onMessage(webSocket: WebSocket, bytes: ByteString) {println("WebSocketListener onMessage  收到消息 bytes ")}override open fun onClosing(webSocket: WebSocket, code: Int, reason: String) {println("WebSocketListener onClosing ")}override open fun onClosed(webSocket: WebSocket, code: Int, reason: String) {println("WebSocketListener onClosed 关闭")}override open fun onFailure(webSocket: WebSocket, t: Throwable, response: Response?) {println("WebSocketListener onFailure 失败")//可以一段延时后再次调用mClient.newWebSocket 重连，见下一段}}

连接websockt服务器，websocket的地址格式是ws://ip:port

       	val mWbSocketUrl = "ws://192.168.124.35:40689" //ip.端口由服务器提供val mClient = OkHttpClient.Builder().pingInterval(10*1000, TimeUnit.SECONDS) //心跳间隔.readTimeout(10*1000, TimeUnit.SECONDS) //设置读取超时时间.writeTimeout(10*1000, TimeUnit.SECONDS) //设置写的超时时间.connectTimeout(10*1000, TimeUnit.SECONDS) //设置连接超时时间.build()val request: Request = Request.Builder().url(mWbSocketUrl).build()mWebSocket = mClient.newWebSocket(request, MyWebSocketListener())

使用

//发送消息mWebSocket?.send("你好"). ..
//关闭连接mWebSocket?.close(1000, null) //状态码和原因

mockwebserver使用

mockwebserver可以让客户端作为一个服务器接收消息，包括http、websocket和其他协议，这里只讲websocket协议
权限

		<uses-permission android:name="android.permission.INTERNET" />

app的build.gradle引入mockwebserver

		implementation 'com.squareup.okhttp3:mockwebserver:5.0.0-alpha.11'

创建监听

val TAG = "WebServerUtil "
var mWebSocket: WebSocket? = nullinner class MyWebSocketListener :WebSocketListener(){override fun onOpen(webSocket: WebSocket, response: Response) {super.onOpen(webSocket, response)//有客户端连接时回调Log.e(TAG, "服务器收到客户端连接成功回调：")//TODO test 这里是演示怎么回消息mWebSocket = webSocketmWebSocket?.send("我是服务器，收到消息")}override fun onMessage(webSocket: WebSocket, bytes: ByteString) {super.onMessage(webSocket, bytes)}override fun onMessage(webSocket: WebSocket, text: String) {super.onMessage(webSocket, text)Log.e(TAG, "服务器收到消息：$text")}override fun onClosed(webSocket: WebSocket, code: Int, reason: String) {super.onClosed(webSocket, code, reason)Log.e(TAG, "onClosed：")}}

创建服务器 注意 mMockWebServer.start(inet4Address,40689) 是我为了方便调试，设置了固定的ip端口，但是这里有端口冲突的可能性。也可以不调用start方法，如果不写start(…)会返回localhost+一个随机端口号。getLocalIpAddress（）方法是我找的一个获取本地ip的工具，我这里把自己手机网络ip设置成服务器ip

			val mMockWebServer = MockWebServer()val response = MockResponse().withWebSocketUpgrade(MyWebSocketListener())val inet4Address = InetAddress.getByName(getLocalIpAddress()) //ip mMockWebServer.start(inet4Address,40689) //ip 端口  固定端口可能出现占用现象，这一行可以去掉，会使用随机端口mMockWebServer.enqueue(response)val websocketUrl = "ws://" + mMockWebServer.hostName + ":" + mMockWebServer.port + "/"println("websocketUrl= $websocketUrl")

最终websocketUrl是服务器的地址，客户端连接服务器时就使用这个地址

			//发送消息给客户端mWebSocket?.send("message"). ..//关闭服务器mMockWebServer.closeQuietly()

附 获取本地ip的方法（需要网络权限）

			private fun getLocalIpAddress(): String? {try {val nilist = Collections.list(NetworkInterface.getNetworkInterfaces())for (ni in nilist) {val ialist = Collections.list(ni.inetAddresses)for (address in ialist) {if (!address.isLoopbackAddress && address is Inet4Address) {return address.getHostAddress()}}}} catch (e: SocketException) {e.printStackTrace()}return ""}