node websocket学习研究

websocket作为不同于http的数据传输方式，是开发一些实时系统的不二选择。

最近在研究开发websocket方面的小程序。小程序客户端直接对websocket做了封装。自己只要写后端就可以了。我拿来测试的后端代码如下，本地环境下小程序可以成功运行。

let websocket = require("websocket");
let http = require("http");
const WebSocketServer = websocket.server;

// 创建一个http Server
let httpServer = http.createServer((request, response) => {
    console.log("received a request");
    response.writeHead(404);
    response.end();
});

// 创建一个websocket Server，websocket Server需要建立在http server之上
let wsServer = new WebSocketServer({
    httpServer: httpServer,
    autoAcceptConnections: true
});

/**
 * 广播所有客户端消息
 * @param  {String} type     广播方式(admin为系统消息，user为用户消息)
 * @param  {String} message  消息
 * @param  {String} nickname 用户昵称，广播方式为admin时可以不存在
 */
function broadcastSend(type, message, nickname) {
    clients.forEach(function(v, i) {
        if (v.ws.readyState === ws.OPEN) {
            v.ws.send(JSON.stringify({
                "type": type,
                "nickname": nickname,
                "message": message
            }));
        }
    })
}
// 事件监听
wsServer.on("connect", (connection) => {
    let clients = [];
    clients.push({
        ws: connection,
        name: 1
    })
    console.log(">>>come from: " + connection.remoteAddress); // 显示连接客户端的ip地址
    connection.on("message", (message) => {
        console.log(message.type);
        console.log(">>>message: ", message); // 接收到信息的类型和内容，注意都是utf8编码
        connection.sendUTF(message.utf8Data + '我是websocket'); // 把接收到的信息发回去

            clients.forEach((v, i) => {
                if (v.ws.readyState === connection.OPEN) {
                    v.ws.send(JSON.stringify({
                        "type": 1,
                        "nickname": 2,
                        "message": 3
                    }));
                }
            })

    });

    connection.on("close", (reasonCode, description) => {
        console.log(connection.remoteAddress + " has disconnected.");
    });
});

// 启动服务器
httpServer.listen(8082, () => {
    console.log(">>>Http Server is listening on port 8082!");
});