「GolangでCUIでWebsocketを試したい」にドンピシャのソースコードはこちら
https://github.com/gorilla/websocket/tree/master/examples/echo
この"server.go"は、client.goからの通信だけではなく、ブラウザの画面も提供します(スゴい！)。
というか、Goプログラムの中に、html書けるなんて知らんかった。
// server.go
// Copyright 2015 The Gorilla WebSocket Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
//go:build ignore
// +build ignore
package main
import (
"flag"
"html/template"
"log"
"net/http"
"github.com/gorilla/websocket"
)
var addr = flag.String("addr", "localhost:8080", "http service address")
var upgrader = websocket.Upgrader{} // use default options
func echo(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 home(w http.ResponseWriter, r *http.Request) {
homeTemplate.Execute(w, "ws://"+r.Host+"/echo")
}
func main() {
flag.Parse()
log.SetFlags(0)
http.HandleFunc("/echo", echo)
http.HandleFunc("/", home)
log.Fatal(http.ListenAndServe(*addr, nil))
}
var homeTemplate = template.Must(template.New("").Parse(`
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<script>
window.addEventListener("load", function(evt) {
var output = document.getElementById("output");
var input = document.getElementById("input");
var ws;
var print = function(message) {
var d = document.createElement("div");
d.textContent = message;
output.appendChild(d);
output.scroll(0, output.scrollHeight);
};
document.getElementById("open").onclick = function(evt) {
if (ws) {
return false;
}
ws = new WebSocket("{{.}}");
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>
<p><input id="input" type="text" value="Hello world!">
<button id="send">Send</button>
</form>
</td><td valign="top" width="50%">
<div id="output" style="max-height: 70vh;overflow-y: scroll;"></div>
</td></tr></table>
</body>
</html>
`))// client.go
// Copyright 2015 The Gorilla WebSocket Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
//go:build ignore
// +build ignore
package main
import (
"flag"
"log"
"net/url"
"os"
"os/signal"
"time"
"github.com/gorilla/websocket"
)
var addr = flag.String("addr", "localhost:8080", "http service address")
func main() {
flag.Parse()
log.SetFlags(0)
interrupt := make(chan os.Signal, 1)
signal.Notify(interrupt, os.Interrupt)
u := url.URL{Scheme: "ws", Host: *addr, Path: "/echo"}
log.Printf("connecting to %s", u.String())
c, _, err := websocket.DefaultDialer.Dial(u.String(), nil)
if err != nil {
log.Fatal("dial:", err)
}
defer c.Close()
done := make(chan struct{})
go func() {
defer close(done)
for {
_, message, err := c.ReadMessage()
if err != nil {
log.Println("read:", err)
return
}
log.Printf("recv: %s", message)
}
}()
ticker := time.NewTicker(time.Second)
defer ticker.Stop()
for {
select {
case <-done:
return
case t := <-ticker.C:
err := c.WriteMessage(websocket.TextMessage, []byte(t.String()))
if err != nil {
log.Println("write:", err)
return
}
case <-interrupt:
log.Println("interrupt")
// Cleanly close the connection by sending a close message and then
// waiting (with timeout) for the server to close the connection.
err := c.WriteMessage(websocket.CloseMessage, websocket.FormatCloseMessage(websocket.CloseNormalClosure, ""))
if err != nil {
log.Println("write close:", err)
return
}
select {
case <-done:
case <-time.After(time.Second):
}
return
}
}
}