golang实现websocket
1.需要的websocket的包：
"github.com/gorilla/websocket"
package main
import (
"github.com/gorilla/websocket"
"learngo/websocket/impl"
"net/http"
"time"
)
var(
upgrader = websocket.Upgrader{
//允许跨域访问
CheckOrigin: func(r *http.Request) bool {
return true
},
}
)
func wsHandler(w http.ResponseWriter, r *http.Request) {
//w.Write([]byte("hello"))
//收到http请求(upgrade),完成websocket协议转换
//在应答的header中放上upgrade:websoket
var (
wsConn *websocket.Conn
err error
data []byte
conn *impl.Connection
)
//Upgrade websocket(返回给客户端的消息)
if wsConn, err = upgrader.Upgrade(w, r, nil); err !=nil {
//报错了，直接返回底层的websocket链接就会终断掉
return
}
if conn, err = impl.InitConnection(wsConn); err != nil {
goto ERR
}
//心跳
go func() {
var(
err error
)
for {
if err = conn.WriteMessage([]byte("heatbeat")); err != nil {
return
}
time.Sleep(5*time.Second)
}
}()
for {
if data, err = conn.ReadMessage(); err != nil {
goto ERR
}
if err = conn.WriteMessage(data); err != nil {
goto ERR
}
}
ERR:
conn.Close()
}
func userHandler(w http.ResponseWriter, r *http.Request) {
w.Write([]byte("Hello World!"))
}
func main() {
//http://localhost:7777/ws
http.HandleFunc("/ws", wsHandler)
http.HandleFunc("/user", userHandler)
//服务端启动
http.ListenAndServe("0.0.0.0:7777", nil)
}
实现模块：线程安全
package main
import (
"github.com/gorilla/websocket"
"net/http"
)
var(
upgrader = websocket.Upgrader{
//允许跨域访问
CheckOrigin: func(r *http.Request) bool {
return true
},
}
)
func wsHandler(w http.ResponseWriter, r *http.Request) {
//w.Write([]byte("hello"))
//收到http请求(upgrade),完成websocket协议转换
//在应答的header中放上upgrade:websoket
var (
conn *websocket.Conn
err error
//msgType int
data []byte
)
if conn, err = upgrader.Upgrade(w, r, nil); err !=nil {
//报错了，直接返回底层的websocket链接就会终断掉
return
}
//得到了websocket.Conn长连接的对象，实现数据的收发
for {
//Text(json), Binary
//if _, data, err = conn.ReadMessage(); err != nil {
if _, data, err = conn.ReadMessage(); err != nil {
//报错关闭websocket
goto ERR
}
//发送数据，判断返回值是否报错
if err = conn.WriteMessage(websocket.TextMessage, data); err != nil {
//报错了
goto ERR
}
}
//error的标签
ERR:
conn.Close()
}
func helloHandler(w http.ResponseWriter, r *http.Request){
w.Write([]byte("Hello World!"))
}
func main() {
//http://localhost:7777/ws
http.HandleFunc("/ws", wsHandler)
http.HandleFunc("/hello", helloHandler)
//服务端启动
http.ListenAndServe("0.0.0.0:7777", nil)
}
js文件：
<!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.innerHTML = message;
output.appendChild(d);
};
document.getElementById("open").onclick = function(evt) {
if (ws) {
return false;
}
ws = new WebSocket("ws://192.168.230.130:7777/ws");
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>
<input id="input" type="text" value="Hello world!">
<button id="send">Send</button>
</form>
</td><td valign="top" width="50%">
<div id="output"></div>
</td></tr></table>
</body>
</html>
