golang实现websocket

发布时间：2020-12-16 09:23:05 所属栏目：大数据来源：网络整理

导读：1.需要的websocket的包： "github.com/gorilla/websocket" package mainimport ("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 {retu

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
		},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,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 _,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>

（编辑：李大同）

【声明】本站内容均来自网络，其相关言论仅代表作者个人观点，不代表本站立场。若无意侵犯到您的权利，请及时与联系站长删除相关内容!