Go语言中websocket的使用demo分享
用户6512516549724 人气:0服务端代码 main.go
package main import ( "errors" "fmt" "net/http" "sync" "time" "github.com/gorilla/websocket" ) // http升级websocket协议的配置 var wsUpgrader = websocket.Upgrader{ // 允许所有CORS跨域请求 CheckOrigin: func(r *http.Request) bool { return true }, } // 客户端读写消息 type wsMessage struct { messageType int data []byte } // 客户端连接 type wsConnection struct { wsSocket *websocket.Conn // 底层websocket inChan chan *wsMessage // 读队列 outChan chan *wsMessage // 写队列 mutex sync.Mutex // 避免重复关闭管道 isClosed bool closeChan chan byte // 关闭通知 } func (wsConn *wsConnection) wsReadLoop() { for { // 读一个message msgType, data, err := wsConn.wsSocket.ReadMessage() if err != nil { goto error } req := &wsMessage{ msgType, data, } // 放入请求队列 select { case wsConn.inChan <- req: case <-wsConn.closeChan: goto closed } } error: wsConn.wsClose() closed: } func (wsConn *wsConnection) wsWriteLoop() { for { select { // 取一个应答 case msg := <-wsConn.outChan: // 写给websocket if err := wsConn.wsSocket.WriteMessage(msg.messageType, msg.data); err != nil { goto error } case <-wsConn.closeChan: goto closed } } error: wsConn.wsClose() closed: } func (wsConn *wsConnection) procLoop() { // 启动一个gouroutine发送心跳 go func() { for { //不断向客户端写数据,其实没有它也是一样的,客户端可以检测到断开 time.Sleep(2 * time.Second) if err := wsConn.wsWrite(websocket.TextMessage, []byte("heartbeat from server")); err != nil { fmt.Println("heartbeat fail") wsConn.wsClose() break } } }() // 这是一个同步处理模型(只是一个例子),如果希望并行处理可以每个请求一个gorutine,注意控制并发goroutine的数量!!! for { msg, err := wsConn.wsRead() if err != nil { fmt.Println("read fail") break } fmt.Println(string(msg.data)) err = wsConn.wsWrite(msg.messageType, msg.data) // 读到数据后,同步的去写数据。应该写成异步 if err != nil { fmt.Println("write fail") break } } } func wsHandler(resp http.ResponseWriter, req *http.Request) { // 应答客户端告知升级连接为websocket wsSocket, err := wsUpgrader.Upgrade(resp, req, nil) if err != nil { return } wsConn := &wsConnection{ wsSocket: wsSocket, inChan: make(chan *wsMessage, 1000), outChan: make(chan *wsMessage, 1000), closeChan: make(chan byte), isClosed: false, } // 处理器 go wsConn.procLoop() // 读协程 go wsConn.wsReadLoop() // 写协程 go wsConn.wsWriteLoop() } func (wsConn *wsConnection) wsWrite(messageType int, data []byte) error { select { case wsConn.outChan <- &wsMessage{messageType, data}: case <-wsConn.closeChan: return errors.New("websocket closed") } return nil } func (wsConn *wsConnection) wsRead() (*wsMessage, error) { select { case msg := <-wsConn.inChan: return msg, nil case <-wsConn.closeChan: } return nil, errors.New("websocket closed") } func (wsConn *wsConnection) wsClose() { wsConn.wsSocket.Close() wsConn.mutex.Lock() defer wsConn.mutex.Unlock() if !wsConn.isClosed { wsConn.isClosed = true close(wsConn.closeChan) } } func main() { http.HandleFunc("/ws", wsHandler) http.ListenAndServe("0.0.0.0:7777", nil) }
前端代码 client.html
<!DOCTYPE html> <html> <head> <meta charset="utf-8"> <script> window.addEventListener("load", function(evt) { const output = document.getElementById("output"); const input = document.getElementById("input"); let ws; const print = function(message) { const d = document.createElement("div"); d.innerHTML = message; output.appendChild(d); }; document.getElementById("open").onclick = function(evt) { if (ws) { return false; } ws = new WebSocket("ws://localhost:7777/ws"); ws.onopen = function(evt) { print("OPEN"); } ws.onclose = function(evt) { print("CLOSE"); ws = null; } ws.onmessage = function(evt) { print("RESPONSE: " + evt.data); } ws.onerror = function(evt) { print("ERROR: " + evt.data); } return false; }; document.getElementById("send").onclick = function(evt) { if (!ws) { return false; } print("SEND: " + input.value); ws.send(input.value); return false; }; document.getElementById("close").onclick = function(evt) { if (!ws) { return false; } ws.close(); return false; }; }); </script> </head> <body> <table> <tr><td valign="top" width="50%"> <p>Click "Open" to create a connection to the server, "Send" to send a message to the server and "Close" to close the connection. You can change the message and send multiple times. </p> <form> <button id="open">Open</button> <button id="close">Close</button> <input id="input" type="text" value="Hello world!"> <button id="send">Send</button> </form> </td><td valign="top" width="50%"> <div id="output"></div> </td></tr></table> </body> </html>
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