websocket的實作方式

前言

利用websocket實作與網頁互動，消息推送點對點消息推送，還有一種springboot的實作，下次再說

配置：

package com.zoo.websocket.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.socket.server.standard.ServerEndpointExporter;

/**
 * @author: 謝飛
 */
@Configuration
public class WebSocketConfig {
    @Bean
    public ServerEndpointExporter serverEndpointExporter() {
        return new ServerEndpointExporter();
    }
}
           

package com.zoo.websocket.server;

import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Component;

import javax.websocket.*;
import javax.websocket.server.PathParam;
import javax.websocket.server.ServerEndpoint;
import java.io.IOException;
import java.util.concurrent.CopyOnWriteArraySet;

/**
 * @author: 謝飛
 */
@Slf4j
@ServerEndpoint("/websocket/server/{sid}")
@Component
public class WebSocketServer {
    //靜态變量，用來記錄目前線上連接配接數。應該把它設計成線程安全的。
    private static int onlineCount = 0;
    //concurrent包的線程安全Set，用來存放每個用戶端對應的MyWebSocket對象。
    private static CopyOnWriteArraySet<WebSocketServer> webSocketSet = new CopyOnWriteArraySet<>();
    //與某個用戶端的連接配接會話，需要通過它來給用戶端發送資料
    private Session session;
    //接收sid
    private String sid = "";

    /**
     * 連接配接建立成功調用的方法
     */
    @OnOpen
    public void onOpen(Session session, @PathParam("sid") String sid) {
        this.session = session;
        //加入set中
        webSocketSet.add(this);
        //線上數加1
        addOnlineCount();
        log.info("有新視窗開始監聽:" + sid + ",目前線上人數為" + getOnlineCount());
        this.sid = sid;
        try {
            sendMessage("連接配接成功");
        } catch (IOException e) {
            log.error("websocket IO異常");
        }
    }

    /**
     * 連接配接關閉調用的方法
     */
    @OnClose
    public void onClose() {
        //從set中删除
        webSocketSet.remove(this);
        //線上數減1
        subOnlineCount();
        log.info("有一連接配接關閉！目前線上人數為" + getOnlineCount());
    }

    /**
     * 收到用戶端消息後調用的方法
     *
     * @param message 用戶端發送過來的消息
     */
    @OnMessage
    public void onMessage(String message, Session session) {
        log.info("收到來自視窗" + sid + "的資訊:" + message);
        //群發消息
        for (WebSocketServer item : webSocketSet) {
            try {
                item.sendMessage(message);
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    /**
     * 發生錯誤
     */
    @OnError
    public void onError(Session session, Throwable error) {
        log.error("發生錯誤");
        error.printStackTrace();
    }

    /**
     * 實作伺服器主動推送
     */
    public void sendMessage(String message) throws IOException {
        this.session.getBasicRemote().sendText(message);
        //this.session.getAsyncRemote().sendText(message);
    }


    /**
     * 群發自定義消息
     */
    public static void sendInfo(String message, @PathParam("sid") String sid) throws IOException {
        log.info("推送消息到視窗" + sid + "，推送内容:" + message);
        for (WebSocketServer item : webSocketSet) {
            try {
                //這裡可以設定隻推送給這個sid的，為null則全部推送
                if (sid == null) {
                    item.sendMessage(message);
                } else if (item.sid.equals(sid)) {
                    item.sendMessage(message);
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    public static synchronized int getOnlineCount() {
        return onlineCount;
    }

    public static synchronized void addOnlineCount() {
        WebSocketServer.onlineCount++;
    }

    public static synchronized void subOnlineCount() {
        WebSocketServer.onlineCount--;
    }
}
           

package com.zoo.websocket.controller;

import com.zoo.base.bean.Resp;
import com.zoo.websocket.server.WebSocketServer;
import org.apache.commons.lang3.StringUtils;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

import java.io.IOException;

/**
 * @author: 謝飛
 */
@Controller
public class TestController {
    @GetMapping("/")
    public String index(String sid, Model model) {
        if (StringUtils.isBlank(sid)) {
            model.addAttribute("websocketUrl", "ws://localhost:3000/websocket/server/null");
        } else {
            model.addAttribute("websocketUrl", "ws://localhost:3000/websocket/server/" + sid);
        }
        return "index";
    }

    //推送資料接口
    @ResponseBody
    @RequestMapping("/push")
    public Resp pushToWeb(String sid, String message) {
        try {
            WebSocketServer.sendInfo(message, sid);
        } catch (IOException e) {
            e.printStackTrace();
            return Resp.fail(sid + "#" + e.getMessage());
        }
        return Resp.ok(sid);
    }

}
           

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.w3.org/1999/xhtml">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<input id="websocketUrl" type="hidden" th:value="${websocketUrl}"/>
</body>
<script>
    var socket;
    if (typeof (WebSocket) == "undefined") {
        console.log("您的浏覽器不支援WebSocket");
    } else {
        console.log("您的浏覽器支援WebSocket");
        //實作化WebSocket對象，指定要連接配接的伺服器位址與端口  建立連接配接
        socket = new WebSocket(document.getElementById("websocketUrl").value);
        //打開事件
        socket.onopen = function () {
            console.log("Socket 已打開");
            //socket.send("這是來自用戶端的消息" + location.href + new Date());
        };
        //獲得消息事件
        socket.onmessage = function (msg) {
            console.log(msg.data);
            //發現消息進入,開始處理前端觸發邏輯
        };
        //關閉事件
        socket.onclose = function () {
            console.log("Socket已關閉");
        };
        //發生了錯誤事件
        socket.onerror = function () {
            alert("Socket發生了錯誤");
            //此時可以嘗試重新整理頁面
        }
    }
</script>
</html>