Golang-websocket编程

末蓝、 2022-11-07 04:15 125阅读 0赞

Go实现websocket编程，需要引入外部包[`gorilla/websocket`][gorilla_websocket]。

我们启动一个http服务器，指定根路径路由到一个html页面，该页面用来模拟websocket通信的客户端，页面会提供一个按钮触发一段执行websocket通信的js。服务端接收到websocket请求，然后将请求的内容完整地响应给浏览器。

接收websocket请求的服务端：

package main
    
    import (
    	"fmt"
    	"net/http"
    
    	"github.com/gorilla/websocket"
    )
    
    var upgrader = websocket.Upgrader{ 
    	ReadBufferSize:  1024,
    	WriteBufferSize: 1024,
    }
    
    func main() { 
    	http.HandleFunc("/echo", func(w http.ResponseWriter, r *http.Request) { 
    		conn, _ := upgrader.Upgrade(w, r, nil) // error ignored for sake of simplicity
    
    		for { 
    			// Read message from browser
    			msgType, msg, err := conn.ReadMessage()
    			if err != nil { 
    				return
    			}
    
    			// Print the message to the console
    			fmt.Printf("%s sent: %s\n", conn.RemoteAddr(), string(msg))
    
    			// Write message back to browser
    			if err = conn.WriteMessage(msgType, msg); err != nil { 
    				return
    			}
    		}
    	})
    
    	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) { 
    		http.ServeFile(w, r, "H:\\go\\main\\websockets.html")
    	})
    
    	http.ListenAndServe(":8080", nil)
    }

发送websocket请求的客户端：

<!DOCTYPE html>
    <html lang="en">
    <head>
        <meta charset="UTF-8">
        <title>WebSockets</title>
    </head>
    <body>
    <input id="input" type="text" />
    <button onclick="send()">Send</button>
    <pre id="output"></pre>
    <script> var input = document.getElementById("input"); var output = document.getElementById("output"); var socket = new WebSocket("ws://localhost:8080/echo"); socket.onopen = function () { output.innerHTML += "Status: Connected\n"; }; socket.onmessage = function (e) { output.innerHTML += "Server: " + e.data + "\n"; }; function send() { socket.send(input.value); input.value = ""; } </script>
    </body>
    </html>

效果：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L21yeWFuZzEyNQ_size_16_color_FFFFFF_t_70]

[gorilla_websocket]: https://github.com/gorilla/websocket
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L21yeWFuZzEyNQ_size_16_color_FFFFFF_t_70]: /images/20221023/85d3856a92d248f3bf399d4e08644a4e.png