個人博客地址：https://blog.yookingh.cn
該文章地址：https://blog.yookingh.cn/dev/190809-webSocket.html
前言
什么是webSocket
WebSocket是一種在單個TCP連接上進行全雙工通信的協(xié)議刽酱。WebSocket通信協(xié)議于2011年被IETF定為標準RFC 6455眠菇，并由RFC7936補充規(guī)范。WebSocket API也被W3C定為標準哨鸭。
WebSocket使得客戶端和服務器之間的數據交換變得更加簡單，允許服務端主動向客戶端推送數據菊卷。在WebSocket API中稻爬，瀏覽器和服務器只需要完成一次握手，兩者之間就直接可以創(chuàng)建持久性的連接斩芭，并進行雙向數據傳輸轻腺。
——摘自百度百科-
應用場景
App與服務器長連接，一般用于通訊划乖。
實踐
框架引入
框架路徑：
Java-WebSocket
OkHttp-GithubPage
//implementation "org.java-websocket:Java-WebSocket:1.4.0"http://
//改用 square項目
implementation 'com.squareup.okhttp3:okhttp:4.0.1'
implementation 'com.squareup.okhttp3:logging-interceptor:4.0.1'
創(chuàng)建Utils類
/**
* @param url webSocket 服務鏈接
* @param listener webSocket 消息回調 - 這里直接使用okhttp的回調/可根據需求另行封裝
*/
class WebSocketUtils(private val url: String, private val listener: WebSocketListener)
初始化webSocket
private const val TAG: String = "WebSocketLog"http://日志抬頭
private const val READ_TIMEOUT: Long = 30//讀取超時
private const val WRITE_TIMEOUT: Long = 30//寫入超時
private const val CONNECT_TIMEOUT: Long = 30//連接超時
private val okHttpClient: OkHttpClient
private var webSocket: RealWebSocket
init{
//引入log日志
val interceptor = HttpLoggingInterceptor(
object : HttpLoggingInterceptor.Logger {
override fun log(message: String) {
Log.d(TAG, message)
}
}
)
interceptor.level = HttpLoggingInterceptor.Level.BODY//日志等級
okHttpClient = OkHttpClient.Builder()
.readTimeout(READ_TIMEOUT, TimeUnit.SECONDS)//設置讀取超時時間
.writeTimeout(WRITE_TIMEOUT, TimeUnit.SECONDS)//設置寫的超時時間
.connectTimeout(CONNECT_TIMEOUT, TimeUnit.SECONDS)//設置連接超時時間
.retryOnConnectionFailure(true)//斷線重連
.addInterceptor(interceptor)//添加攔截器
.build()
val request: Request = Request.Builder().url(url).build()
//創(chuàng)建webSocket
webSocket = okHttpClient.newWebSocket(request, listener) as RealWebSocket
}
基本方法封裝
//發(fā)送
fun send(message: String) {
//這里message為與后臺約定的內容 建議使用Json樣式
val isSend = webSocket.send(message)
//發(fā)送失敗可以做重新發(fā)送
Log.d(TAG, "send-->isSend:$isSend message:$message")
}
//重連
fun reConnect(url: String) {//替換了url
webSocket.cancel()
val request: Request = Request.Builder().url(url).build()
webSocket = okHttpClient.newWebSocket(request, listener) as RealWebSocket
}
fun reConnect() {//未替換url
reConnect(url)
}
//斷開
fun cancel() {
webSocket.cancel()
}
心跳機制處理
心跳的啟動與關閉封裝
private const val WHAT_HEART: Int = 0//handler-what
private const val DEFAULT_HEART_TIME: Long = 60//默認心跳時間
/**
* @param heartMessage 向后臺服務發(fā)送的心跳消息
* @param current 間隔時間
*/
fun startHeart(heartMessage: String, current: Long?) {
this.heartMessage = heartMessage
heartTime = current!!
handler.sendEmptyMessage(WHAT_HEART)
}
//停止心跳
fun endHeart() {
handler.removeMessages(WHAT_HEART)
}
心跳Handler
//這里使用靜態(tài)內部類 防止內存泄漏
companion object {
private class WithoutLeakHandler(wsu: WebSocketUtils) : Handler() {
private val mWsu: WeakReference<WebSocketUtils> = WeakReference(wsu)
override fun handleMessage(msg: Message?) {
super.handleMessage(msg)
val webSocketUtils = mWsu.get()!!
//調用發(fā)送方法向后臺服務發(fā)送心跳信息
webSocketUtils.send(webSocketUtils.heartMessage)
//webSocketUtils.heartTime之后再次發(fā)送心跳信息
msg!!.target.sendEmptyMessageDelayed(WHAT_HEART, webSocketUtils.heartTime)
}
}
}
private var handler: Handler = WithoutLeakHandler(this)
方法調用
webSocketUtils = WebSocketUtils(url,object : WebSocketListener() {
override fun onOpen(webSocket: WebSocket, response: Response) {
super.onOpen(webSocket, response)
Log.d(TAG, "onOpen")
}
override fun onMessage(webSocket: WebSocket, text: String) {
super.onMessage(webSocket, text)
Log.d(TAG, "onMessage-->text:$text")
}
override fun onMessage(webSocket: WebSocket, bytes: ByteString) {
super.onMessage(webSocket, bytes)
Log.d(TAG, "onMessage-->bytes:$bytes")
}
override fun onClosed(webSocket: WebSocket, code: Int, reason: String) {
super.onClosed(webSocket, code, reason)
Log.d(TAG, "onClosed-->code:$code\treason$reason")
webSocketUtils.endHeart()//停止心跳
}
override fun onClosing(webSocket: WebSocket, code: Int, reason: String) {
super.onClosing(webSocket, code, reason)
Log.d(TAG, "onClosing-->code:$code\treason$reason")
webSocketUtils.endHeart()//停止心跳
}
override fun onFailure(webSocket: WebSocket, t: Throwable, response: Response?) {
super.onFailure(webSocket, t, response)
Log.d(TAG, "onFailure-->throwable:$t")
//webSocketUtils.reConnect()
webSocketUtils.endHeart()//停止心跳
}
})
webSocketUtils.startHeart("心跳消息", 1000)//啟動心跳
Demo
補充
建議使用Service進行webSocket連接
