Websocket通信教程

博主是基于消息公共组件做的，其中包含了站内消息，以及邮件、短信等，使用ActiveMQ做了消息解耦，webwocket实现的站内消息模块。

Websocket是h5提供的一种协议，全双工模式的，采用TCP协议进行通信，只要一次握手，就能持续交互。直接上代码

第一步先构建websocket服务器及其相应的配置

package com.chinacreator.c2.websocket;

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
import com.chinacreator.c2.common.CustomSEnum;
import com.chinacreator.c2.common.utils.RedisTools;
import org.apache.commons.lang.StringUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.StringRedisTemplate;
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.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.stream.Collectors;

@Component
@ServerEndpoint("/websocketServer/{type}/{username}/{randomId}")
public class WebSocketServer {

    /**
     * 以用户的姓名为key，WebSocket为对象保存起来
     */
    private static Map clients = new ConcurrentHashMap<>();

    /**
     * 会话
     */
    private Session session;

    /**
     * 业务类型
     */
    private String type;

    /**
     * 用户名
     */
    private String username;

    /**
     * 随机数
     */
    private String randomId;

    @Autowired
    private StringRedisTemplate stringRedisTemplate;

    @OnOpen
    public void onOpen(@PathParam("type") String type,@PathParam("username") String username,@PathParam("randomId") String randomId, Session session) {
        System.out.println("打开连接");
        String key = type + "-" + username + "-" + randomId;
        this.session = session;
        this.type = type;
        this.username = username;
        this.randomId = randomId;
        clients.put(key,this);
    }

    @OnError
    public void onError(Session session, Throwable error) {
        System.out.print("用户错误："+this.username+"，错误信息："+error.getMessage());
    }

    @OnClose
    public void onClose() {
        String key = type + "-" + username + "-" + randomId;
        clients.remove(key);
    }

    @OnMessage
    public void onMessage(String message, Session session) {
        System.out.println("用户消息:"+username+",报文:"+message);
        JSONObject jsonObject = JSON.parseObject(message);
        String t = (String) jsonObject.get("type");
        String receiver = (String) jsonObject.get("receiver");
        String msg = (String) jsonObject.get("msg");
        String filters = t + "-" + receiver;
        Map client = parseMapForFilter(clients,filters);
        for(WebSocketServer webSocketServer : client.values()){
            webSocketServer.session.getAsyncRemote().sendText(msg);
        }
    }


    /**
     * 从map中查询想要的map项，根据key
     */
    public static Map parseMapForFilter(Map map,String filters) {
        if (map == null) {
            return null;
        } else {
            map = map.entrySet().stream()
                    .filter((e) -> checkKey(e.getKey(),filters))
                    .collect(Collectors.toMap(
                            (e) -> (String) e.getKey(),
                            (e) -> e.getValue()
                    ));
        }
        return map;
    }

    /**
     * 通过indexof匹配想要查询的字符
     */
    private static boolean checkKey(String key,String filters) {
        if (key.indexOf(filters) > -1) {
            return true;
        } else {
            return false;
        }
    }

    /**
     * 发送自定义消息
     * @param message
     * @param username
     * @throws IOException
     */
    public static void sendInfo(String message,@PathParam("username") String username) throws IOException {
        System.out.println("发送消息到:"+username+"，报文:"+message);
        JSONObject jsonObject = JSON.parseObject(message);
        String t = (String) jsonObject.get("type");
        String receiver = (String) jsonObject.get("receiver");
        String msg = (String) jsonObject.get("msg");
        String filters = t + "-" + receiver;
        Map client = parseMapForFilter(clients,filters);
        for(WebSocketServer webSocketServer : client.values()){
            webSocketServer.session.getAsyncRemote().sendText(msg);
        }
    }
}

package com.chinacreator.c2.websocket;

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

/***
 * 用于注册ServerEndpoint
 */
@Configuration
public class WebSocketConfig {
    @Bean
    public ServerEndpointExporter serverEndpointExporter() {
        return new ServerEndpointExporter();
    }
}

 

接着是做一个客户端

 var socketUrl="http://localhost:8081/websocketServer/1/123456/www";
            socketUrl=socketUrl.replace("https","ws").replace("http","ws");
            console.log(socketUrl);
            if(socket!=null){
                socket.close();
                socket=null;
            }
            socket = new WebSocket(socketUrl);
            //打开事件
            socket.onopen = function() {
                console.log("websocket已打开");
                //socket.send("这是来自客户端的消息" + location.href + new Date());
            };
            //获得消息事件
            socket.onmessage = function(msg) {
               console.log(msg.data);
                //发现消息进入    开始处理前端触发逻辑
            };
            //关闭事件
            socket.onclose = function() {
                console.log("websocket已关闭");
            };
            //发生了错误事件
            socket.onerror = function() {
                console.log("websocket发生了错误");
            }

 

服务端发送消息至客户端

JSONObject paramObj1 = new JSONObject();
        paramObj1.put("type","1");
        paramObj1.put("receiver","123456");
        paramObj1.put("msg","你好呢，我是服务端");
        WebSocketServer.sendInfo(JSONObject.toJSONString(paramObj1),"123456");

成功接收到消息