webSocket-全双工通信协议

发布时间 2023-06-09 10:50:57作者: 谭五月

1、springboot2.0集成webSocket

项目结构

img


maven依赖
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.6.RELEASE</version>
    </parent>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <!-- websocket dependency -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-websocket</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>
    </dependencies>

核心代码
@ServerEndpoint(value = "/ws/asset")
@Component
public class WebSocketServer {

    @PostConstruct
    public void init() {
        System.out.println("websocket 加载");
    }
    private static Logger log = LoggerFactory.getLogger(WebSocketServer.class);
    private static final AtomicInteger OnlineCount = new AtomicInteger(0);
    // concurrent包的线程安全Set,用来存放每个客户端对应的Session对象。
    private static CopyOnWriteArraySet<Session> SessionSet = new CopyOnWriteArraySet<Session>();


    /**
     * 连接建立成功调用的方法
     */
    @OnOpen
    public void onOpen(Session session) {
        SessionSet.add(session);
        int cnt = OnlineCount.incrementAndGet(); // 在线数加1
        log.info("有连接加入,当前连接数为:{}", cnt);
        SendMessage(session, "连接成功");
    }

    /**
     * 连接关闭调用的方法
     */
    @OnClose
    public void onClose(Session session) {
        SessionSet.remove(session);
        int cnt = OnlineCount.decrementAndGet();
        log.info("有连接关闭,当前连接数为:{}", cnt);
    }

    /**
     * 收到客户端消息后调用的方法
     *
     * @param message
     *            客户端发送过来的消息
     */
    @OnMessage
    public void onMessage(String message, Session session) {
        log.info("来自客户端的消息:{}",message);
        SendMessage(session, "收到消息,消息内容:"+message);

    }

    /**
     * 出现错误
     * @param session
     * @param error
     */
    @OnError
    public void onError(Session session, Throwable error) {
        log.error("发生错误:{},Session ID: {}",error.getMessage(),session.getId());
        error.printStackTrace();
    }

    /**
     * 发送消息,实践表明,每次浏览器刷新,session会发生变化。
     * @param session
     * @param message
     */
    public static void SendMessage(Session session, String message) {
        try {
            session.getBasicRemote().sendText(String.format("%s (From Server,Session ID=%s)",message,session.getId()));
        } catch (IOException e) {
            log.error("发送消息出错:{}", e.getMessage());
            e.printStackTrace();
        }
    }

    /**
     * 群发消息
     * @param message
     * @throws IOException
     */
    public static void BroadCastInfo(String message) throws IOException {
        for (Session session : SessionSet) {
            if(session.isOpen()){
                SendMessage(session, message);
            }
        }
    }

    /**
     * 指定Session发送消息
     * @param sessionId
     * @param message
     * @throws IOException
     */
    public static void SendMessage(String message,String sessionId) throws IOException {
        Session session = null;
        for (Session s : SessionSet) {
            if(s.getId().equals(sessionId)){
                session = s;
                break;
            }
        }
        if(session!=null){
            SendMessage(session, message);
        }
        else{
            log.warn("没有找到你指定ID的会话:{}",sessionId);
        }
    }

}

ServerEndpointExporter对象创建
@Configuration
public class WebSocketConfig {

    @Bean
    public ServerEndpointExporter serverEndpointExporter () {
        return new ServerEndpointExporter();
    }
}

测试Controller
@RestController
@RequestMapping("/api/ws")
public class WebSocketController {


    /**
     * 群发消息内容
     * @param message
     * @return
     */
    @RequestMapping(value="/sendAll", method= RequestMethod.GET)
    public String sendAllMessage(@RequestParam(required=true) String message){
        try {
            WebSocketServer.BroadCastInfo(message);
        } catch (IOException e) {
            e.printStackTrace();
        }
        return "ok";
    }
    
    /**
     * 指定会话ID发消息
     * @param message 消息内容
     * @param id 连接会话ID
     * @return
     */
    @RequestMapping(value="/sendOne", method=RequestMethod.GET)
    public String sendOneMessage(@RequestParam(required=true) String message,@RequestParam(required=true) String id){
        try {
            WebSocketServer.SendMessage(message,id);
        } catch (IOException e) {
            e.printStackTrace();
        }
        return "ok";
    }
}

index.html
<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <title>websocket测试</title>
    <style type="text/css">
        h3,h4{
            text-align:center;
        }
    </style>
</head>
<body>

<h3>WebSocket测试,在<span style="color:red">控制台</span>查看测试信息输出!</h3>
<h4>
    [url=/api/ws/sendOne?message=单发消息内容&id=none]单发消息链接[/url]
    [url=/api/ws/sendAll?message=群发消息内容]群发消息链接[/url]
</h4>


<script type="text/javascript">
    var socket;
    if (typeof (WebSocket) === undefined) {
        console.error("遗憾:您的浏览器不支持WebSocket");
    } else {
        socket = new WebSocket("ws://localhost:7300/webSocket");
        //连接打开事件
        socket.onopen = function() {
            console.log("Socket 已打开");
            socket.send("消息发送测试(From Client)");
        };
        
        //收到消息事件
        socket.onmessage = function(msg) {
            console.log(msg.data);
        };
        
            //连接关闭事件
        socket.onclose = function() {
            console.log("Socket已关闭");
        };
        
        //发生了错误事件
        socket.onerror = function() {
            alert("Socket发生了错误");
        };
    
        //窗口关闭时,关闭连接
        window.unload=function() {
            socket.close();
        };
    }
</script>

</body>
</html>

2、websocket建立连接时传递参数

时间 2017-06-20

标签 websocket

原文 [http://blog.csdn.net/u014803081/article/details/73498233](javascript:void())

后台获取参数4种方法:

前端websocket的url
"ws:localhost:82/chat/123?username=ydh";
后端socket的注释
@ServerEndpoint("/chat/{param}")
socket的open方法
@OnOpen
public void open(Session session, @PathParam("param")String  param) {
    System.out.println("用户"+param+" 登录");

    Map<String, String> map = session.getPathParameters();
    System.out.println("session.getPathParameters()"+map.toString());

    String str = session.getQueryString();
    System.out.println("session.getQueryString()"+str);

    String uri = session.getRequestURI().toString();
    System.out.println("session.getRequestURI().toString()"+uri);

}
结果
用户123 登录
session.getPathParameters(){param=123}
session.getQueryString()username=baidu
session.getRequestURI().toString()/chat/123?username=baidu

1、url站位,通过@PathParam注释获取
2、url站位,通过session.getPathParameters()获取
3、url传参,通过session.getQueryString()
4、url传参,通过session.getRequestURI().toString()

从结果可以看出1、2两个方法不需要截取,可以直接使用;而3、4两个方法都需要截取字符串,稍微麻烦,但是请求的url比较清爽。