Golang如何使用websocket

一时失言乱红尘 2022-05-22 05:25 133阅读 0赞

## 下载websocket包 ##

$ go get golang.org/x/net/websocket

如果下载失败,可能是被墙了。

> package golang.org/x/net/websocket: unrecognized import path “golang.org/x/net/websocket” (https fetch: Get [https://golang.org/x/net/websocket?go-get=1][https_golang.org_x_net_websocket_go-get_1]: dial tcp 216.239.37.1:443: connectex: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond.)

可以尝试

$ go get -u github.com/golang/net/websocket

下载后记得将路径改成golang.org/x/net/websocket

$ cd $GOPATH
    $ mkdir -p golang.org/x/net
    $ cp github.com/golang/net/websocket/  golang.org/x/net/ -R

## 实例 ##

### 服务端代码 ###

server.go

package main
    
    import (  
    
        "fmt"   
    
        "golang.org/x/net/websocket" 
    
        "html/template"              //支持模板html 
    
        "log"  
    
        "net/http"  
    
    )
    
    func Echo(ws *websocket.Conn) {  
    
        var err error  
    
        for {  
    
            var reply string  
    
            //websocket接受信息 
    
            if err = websocket.Message.Receive(ws, &reply); err != nil {  
    
                fmt.Println("receive failed:", err)  
    
                break  
    
            }
    
            fmt.Println("reveived from client: " + reply)
    
            msg := "received:" + reply
    
            fmt.Println("send to client:" + msg)
    
            //这里是发送消息
    
            if err = websocket.Message.Send(ws, msg); err != nil {
    
                fmt.Println("send failed:", err)
    
                break
    
            }
    
        }
    
    }
    
    func web(w http.ResponseWriter, r *http.Request) {  
    
        //打印请求的方法 
    
        fmt.Println("method", r.Method)  
    
        if r.Method == "GET" { //如果请求方法为get显示login.html,并相应给前端 
    
            t, _ := template.ParseFiles("websocket.html")  
    
            t.Execute(w, nil)  
    
        } else {  
    
            //否则走打印输出post接受的参数username和password 
    
            fmt.Println(r.PostFormValue("username"))  
    
            fmt.Println(r.PostFormValue("password"))  
    
        }  
    
    }
    
    func main() {
    
        //接受websocket的路由地址
    
        http.Handle("/websocket", websocket.Handler(Echo))
    
        //html页面
    
        http.HandleFunc("/web", web)
    
        if err := http.ListenAndServe(":1234", nil); err != nil {
    
            log.Fatal("ListenAndServe:", err)
    
        }
    
    }

### 客户端代码 ###

websocket.html

<!DOCTYPE html>
    
     <html>
    
    <head>
    
        <meta charset="utf-8"/>
    
        <title>go测试socket</title>
    
    </head>
    
    <body>
    
        <script type="text/javascript"> var sock = null; var wsuri = "ws://127.0.0.1:1234/websocket"; window.onload = function() { console.log("onload"); sock = new WebSocket(wsuri); sock.onopen = function() { console.log("connected to " + wsuri); } sock.onclose = function(e) { console.log("connection closed (" + e.code + ")"); } sock.onmessage = function(e) { console.log("message received: " + e.data); } }; function send() { var msg = document.getElementById('message').value; sock.send(msg); }; </script>
    
        <h1>WebSocket Echo Test</h1>
    
        <form>
    
            <p>
    
                Message: <input id="message" type="text" value="Hello, world!">
    
            </p>
    
        </form>
    
        <button onclick="send();">Send Message</button>
    
    </body>
    
    </html>

## 测试 ##

**启动服务端**

$ ./server

**启动浏览器**  
输入[http://127.0.0.1:1234/web][http_127.0.0.1_1234_web]

![这里写图片描述][70]

网络通信内容如图所示，首先加载页面，接着使用HTTP建立websocket连接，后续通信直接使用websocket进行。

点击 页面中SendMessage按钮

server端输出：

> method GET  
> reveived from client: Hello, world!  
> send to client:received:Hello, world!

浏览器输出：

![这里写图片描述][70 1]

## 参考 ##

[https://github.com/astaxie/build-web-application-with-golang/blob/master/zh/08.2.md][https_github.com_astaxie_build-web-application-with-golang_blob_master_zh_08.2.md]

[https://github.com/ukai/go-websocket-sample/blob/master/websocket\_echo\_sample.go][https_github.com_ukai_go-websocket-sample_blob_master_websocket_echo_sample.go]

[https_golang.org_x_net_websocket_go-get_1]: https://golang.org/x/net/websocket?go-get=1
[http_127.0.0.1_1234_web]: http://127.0.0.1:1234/web
[70]: /images/20220522/f9abbaf460d34fa68543348557782414.png
[70 1]: /images/20220522/0e4d86738cbd44fdb8238bbab7c852aa.png
[https_github.com_astaxie_build-web-application-with-golang_blob_master_zh_08.2.md]: https://github.com/astaxie/build-web-application-with-golang/blob/master/zh/08.2.md
[https_github.com_ukai_go-websocket-sample_blob_master_websocket_echo_sample.go]: https://github.com/ukai/go-websocket-sample/blob/master/websocket_echo_sample.go