WebSocket

Using net WebSocket

Server

server.go

  1. package main
  3. import (
  4.     "fmt"
  6.     "github.com/labstack/echo"
  7.     "github.com/labstack/echo/middleware"
  8.     "golang.org/x/net/websocket"
  9. )
  11. func hello(c echo.Context) error {
  12.     websocket.Handler(func(ws *websocket.Conn) {
  13.         defer ws.Close()
  14.         for {
  15.             // Write
  16.             err := websocket.Message.Send(ws, "Hello, Client!")
  17.             if err != nil {
  18.                 c.Logger().Error(err)
  19.             }
  21.             // Read
  22.             msg := ""
  23.             err = websocket.Message.Receive(ws, &msg)
  24.             if err != nil {
  25.                 c.Logger().Error(err)
  26.             }
  27.             fmt.Printf("%s\n", msg)
  28.         }
  29.     }).ServeHTTP(c.Response(), c.Request())
  30.     return nil
  31. }
  33. func main() {
  34.     e := echo.New()
  35.     e.Use(middleware.Logger())
  36.     e.Use(middleware.Recover())
  37.     e.Static("/", "../public")
  38.     e.GET("/ws", hello)
  39.     e.Logger.Fatal(e.Start(":1323"))
  40. }

Using gorilla WebSocket

Server

server.go

  1. package main
  3. import (
  4.     "fmt"
  6.     "github.com/gorilla/websocket"
  7.     "github.com/labstack/echo"
  8.     "github.com/labstack/echo/middleware"
  9. )
  11. var (
  12.     upgrader = websocket.Upgrader{}
  13. )
  15. func hello(c echo.Context) error {
  16.     ws, err := upgrader.Upgrade(c.Response(), c.Request(), nil)
  17.     if err != nil {
  18.         return err
  19.     }
  20.     defer ws.Close()
  22.     for {
  23.         // Write
  24.         err := ws.WriteMessage(websocket.TextMessage, []byte("Hello, Client!"))
  25.         if err != nil {
  26.             c.Logger().Error(err)
  27.         }
  29.         // Read
  30.         _, msg, err := ws.ReadMessage()
  31.         if err != nil {
  32.             c.Logger().Error(err)
  33.         }
  34.         fmt.Printf("%s\n", msg)
  35.     }
  36. }
  38. func main() {
  39.     e := echo.New()
  40.     e.Use(middleware.Logger())
  41.     e.Use(middleware.Recover())
  42.     e.Static("/", "../public")
  43.     e.GET("/ws", hello)
  44.     e.Logger.Fatal(e.Start(":1323"))
  45. }

Client

index.html

  1. <!doctype html>
  2. <html lang="en">
  4. <head>
  5.   <meta charset="utf-8">
  6.   <title>WebSocket</title>
  7. </head>
  9. <body>
  10.   <p id="output"></p>
  12.   <script>
  13.     var loc = window.location;
  14.     var uri = 'ws:';
  16.     if (loc.protocol === 'https:') {
  17.       uri = 'wss:';
  18.     }
  19.     uri += '//' + loc.host;
  20.     uri += loc.pathname + 'ws';
  22.     ws = new WebSocket(uri)
  24.     ws.onopen = function() {
  25.       console.log('Connected')
  26.     }
  28.     ws.onmessage = function(evt) {
  29.       var out = document.getElementById('output');
  30.       out.innerHTML += evt.data + '<br>';
  31.     }
  33.     setInterval(function() {
  34.       ws.send('Hello, Server!');
  35.     }, 1000);
  36.   </script>
  37. </body>
  39. </html>

Output

Client

  1. Hello, Client!
  2. Hello, Client!
  3. Hello, Client!
  4. Hello, Client!
  5. Hello, Client!

Server

  1. Hello, Server!
  2. Hello, Server!
  3. Hello, Server!
  4. Hello, Server!
  5. Hello, Server!

Source Code

Maintainers