前言

实践是检验真理的唯一标准

正文

如何将Gin框架的后端与WebSocket服务写在一起, 以达到共用一个端口的情况呢?
我们来看单纯使用 net 包和 WS 结合

package main
import (
    "flag"
    "fmt"
    "log"
    "net/http"
    "github.com/gorilla/websocket"
)
var addr = flag.String("addr", "localhost:8080", "http service address")
var upgrader = websocket.Upgrader{
    // 解决跨域问题
    CheckOrigin: func(r *http.Request) bool {
        return true
    },
} // use default options
func ws(w http.ResponseWriter, r *http.Request) {
    c, err := upgrader.Upgrade(w, r, nil)
    if err != nil {
        log.Print("upgrade:", err)
        return
    }
    defer c.Close()
    for {
        mt, message, err := c.ReadMessage()
        if err != nil {
            log.Println("read:", err)
            break
        }
        log.Printf("recv: %s", message)
        err = c.WriteMessage(mt, message)
        if err != nil {
            log.Println("write:", err)
            break
        }
    }
}
func main() {
    flag.Parse()
    log.SetFlags(0)
    http.HandleFunc("/ws", ws)
    fmt.Println(*addr)
    log.Fatal(http.ListenAndServe(*addr, nil))
}

其实本质来说, WS服务在握手的过程中最开始也是HTTP请求, 然后再 Upgrade 到WS模式的, Upgrade函数接受三个参数, 一个是返回值套接字, 一个是请求套接字, 一个是返回值的头, 而对于 Gin 的上下文 gin.Context 来说也是有这些数据的, 因此我们修改成

package control
import (
    "log"
    "net/http"
    "github.com/gin-gonic/gin"
    "github.com/gorilla/websocket"
)
var upgrader = websocket.Upgrader{
    // 解决跨域问题
    CheckOrigin: func(r *http.Request) bool {
        return true
    },
} // use default options
func cmdWebSocket(c *gin.Context) {
    ws, err := upgrader.Upgrade(c.Writer, c.Request, nil)
    if err != nil {
        log.Print("upgrade:", err)
        return
    }
    defer ws.Close()
    for {
        mt, message, err := ws.ReadMessage()
        if err != nil {
            log.Println("read:", err)
            break
        }
        log.Printf("recv: %s", message)
        err = ws.WriteMessage(mt, message)
        if err != nil {
            log.Println("write:", err)
            break
        }
    }
}

即可
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作者：ChnMig
出处：https://www.cnblogs.com/chnmig/p/14463837.html