1.websocket 介紹
WebSocket協議是基於TCP的一種新的網絡協議。它實現了瀏覽器與服務器全雙工(full-duplex)通信——允許服務器主動發送信息給客戶端。
《WebSocket實現實時雙向通信》已經介紹java與android如何基於websocket通信。
2.實現
在golang語言中，目前有兩種比較常用的實現方式：一個是golang自帶的庫，另一個是gorilla，功能強大。
go get github.com/gorilla/websocket
websocket實現代碼
package gowebsocket
import (
"encoding/json"
"goweb/common/response"
"log"
"net/http"
"strconv"
"github.com/gin-gonic/gin"
"github.com/gorilla/websocket"
)
// ClientManager is a websocket manager
type ClientManager struct {
Clients map[*Client]bool
Broadcast chan []byte
Register chan *Client
Unregister chan *Client
}
// Client is a websocket client
type Client struct {
ID int
Socket *websocket.Conn
Send chan []byte
}
// Message is return msg
type Message struct {
Sender string `json:"sender,omitempty"`
Recipient string `json:"recipient,omitempty"`
Content string `json:"content,omitempty"`
}
// Manager define a ws server manager
var Manager = ClientManager{
Broadcast: make(chan []byte),
Register: make(chan *Client),
Unregister: make(chan *Client),
Clients: make(map[*Client]bool),
}
//啓動websocket服務
// Start is 項目運行前, 協程開啓start -> go Manager.Start()
func (manager *ClientManager) Start() {
for {
log.Println("<---管道通信--->")
select {
case conn := <-Manager.Register:
log.Printf("新用戶加入:%v", conn.ID)
Manager.Clients[conn] = true
jsonMessage, _ := json.Marshal(&Message{Content: "Successful connection to socket service"})
Manager.Send(jsonMessage, conn)
case conn := <-Manager.Unregister:
log.Printf("用戶離開:%v", conn.ID)
if _, ok := Manager.Clients[conn]; ok {
close(conn.Send)
delete(Manager.Clients, conn)
jsonMessage, _ := json.Marshal(&Message{Content: "A socket has disconnected"})
Manager.Send(jsonMessage, conn)
}
case message := <-Manager.Broadcast:
jsonMessage, _ := json.Marshal(&Message{Content: string(message)})
for conn := range Manager.Clients {
select {
case conn.Send <- jsonMessage:
default:
close(conn.Send)
delete(Manager.Clients, conn)
}
}
}
}
}
// Send is to send ws message to ws client
func (manager *ClientManager) Send(message []byte, ignore *Client) {
for conn := range manager.Clients {
// if conn != ignore { //向除了自己的socket 用戶發送
conn.Send <- message
// }
}
}
func (c *Client) Read() {
defer func() {
Manager.Unregister <- c
c.Socket.Close()
}()
for {
_, message, err := c.Socket.ReadMessage()
if err != nil {
Manager.Unregister <- c
c.Socket.Close()
break
}
log.Printf("讀取到客戶端的信息:%s", string(message))
Manager.Broadcast <- message
}
}
func (c *Client) Write() {
defer func() {
c.Socket.Close()
}()
for {
select {
case message, ok := <-c.Send:
if !ok {
c.Socket.WriteMessage(websocket.CloseMessage, []byte{})
return
}
log.Printf("發送到到客戶端的信息:%s", string(message))
c.Socket.WriteMessage(websocket.TextMessage, message)
}
}
}
// xxx/ws/2 2表示客戶端userId 編號
//WsHandler socket 連接 中間件 作用:升級協議,用戶驗證,自定義信息等
func WsHandler(c *gin.Context) {
userId, err := strconv.Atoi(c.Param("userId"))
if err != nil {
response.FailResult(http.StatusBadRequest, err.Error(), c)
return
}
conn, err := websocket.Upgrade(c.Writer, c.Request, nil, 1024, 1024)
if err != nil {
http.NotFound(c.Writer, c.Request)
return
}
//可以添加用戶信息驗證
client := &Client{
ID: userId,
Socket: conn,
Send: make(chan []byte),
}
Manager.Register <- client
go client.Read()
go client.Write()
}
入口引用
go gowebsocket.Manager.Start()
this.GET("/ws/:userId", gowebsocket.WsHandler)測試
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title></title>
<style type="text/css">
.body{text-align: center;}
#open{width: 120px;height: 35px;}
#close{width: 120px;height: 35px;}
#text{display: inline-block;margin: auto;margin-top: 10px;margin-bottom: 10px;width: 240px;}
</style>
</head>
<body class="body">
<button id="open">打開連接</button>
<button id="close">關閉連接</button>
<br/>
<input type="text" name="text" id="text" value="" />
<br/>
<button id="send">發送</button>
<div id="msg">
</div>
</body>
<script>
var openbtn = document.getElementById("open")
var closebtn = document.getElementById("close")
var text = document.getElementById("text")
var send = document.getElementById("send")
var msg = document.getElementById("msg")
var websocket
openbtn.onclick = function(){
websocket = new WebSocket("ws://localhost:8080/api/v1/ws")
websocket.onopen=function(){
console.log("connected");
}
websocket.onmessage = function(e){
console.log(e);
msg.innerHTML += '<br/>接收：'+e.data;
}
websocket.onclose=function(e){
console.log("closed",e);
}
}
closebtn.onclick=function(){
websocket.close(1000,"close")
}
send.onclick=function(){
var msg = text.value
websocket.send(msg)
}
</script>
</html>