美文网首页Snippet
最简单的java websocket demo

最简单的java websocket demo

作者: higher2017 | 来源:发表于2016-12-28 11:41 被阅读676次

本demo参考至:《Java WebSocket编程开发、部署和保护动态Web应用》

服务端代码:

import java.io.IOException;
import java.util.Set;
import java.util.concurrent.CopyOnWriteArraySet;
import java.util.concurrent.atomic.AtomicInteger;

import javax.websocket.OnClose;
import javax.websocket.OnError;
import javax.websocket.OnMessage;
import javax.websocket.OnOpen;
import javax.websocket.Session;
import javax.websocket.server.ServerEndpoint;

import org.apache.log4j.Logger;

/**
 * 该注解用来指定一个URI,客户端可以通过这个URI来连接到WebSocket。 相当于SpringMVC的@RequestMapping("/*")注解
 * 
 * @author higher2016
 * @2016-12-28
 */
@ServerEndpoint("/echo")
public class EchoController {

    private static final Logger logger = Logger.getLogger(EchoController.class);

    private static final String GUEST_PREFIX = "Guest";
    private static final AtomicInteger connectionIds = new AtomicInteger(0);
    private static final Set<EchoController> connections = new CopyOnWriteArraySet<EchoController>();

    private final String nickname;
    private Session session;

    public EchoController() {
        nickname = GUEST_PREFIX + connectionIds.getAndIncrement();
    }

    @OnOpen
    public void start(Session session) {
        this.session = session;
        connections.add(this);
        String message = String.format("* %s %s", nickname, "has joined.");
        broadcast(message);
    }

    @OnClose
    public void end() {
        connections.remove(this);
        String message = String.format("* %s %s", nickname, "has disconnected.");
        broadcast(message);
    }
        
    /**
     * 收到客户端消息后调用的方法
     * 
     * @param incomingMessage
     *            客户端发送过来的消息
     */
    @OnMessage
    public void incoming(String message) {
        String filteredMessage = String.format("%s: %s", nickname, message.toString());
        broadcast(filteredMessage);
    }

    @OnError
    public void onError(Throwable t) throws Throwable {
        logger.error("Chat Error: " + t.toString(), t);
    }

    private static void broadcast(String msg) {
        for (EchoController client : connections) {
            try {
                synchronized (client) {
                    client.session.getBasicRemote().sendText(msg);
                }
            } catch (IOException e) {
                logger.debug("Chat Error: Failed to send message to client", e);
                connections.remove(client);
                try {
                    client.session.close();
                } catch (IOException e1) {
                }
                String message = String.format("* %s %s", client.nickname, "has been disconnected.");
                broadcast(message);
            }
        }
    }
}

客户端jsp:

<!DOCTYPE html>
<html>
<head>
    <title>Apache Tomcat WebSocket Examples: Chat</title>
    <style type="text/css">
        input#chat {
            width: 410px
        }

        #console-container {
            width: 400px;
        }

        #console {
            border: 1px solid #CCCCCC;
            border-right-color: #999999;
            border-bottom-color: #999999;
            height: 170px;
            overflow-y: scroll;
            padding: 5px;
            width: 100%;
        }

        #console p {
            padding: 0;
            margin: 0;
        }
    </style>
    <script type="text/javascript">
        var Chat = {};

        Chat.socket = null;

        Chat.connect = (function(host) {
            if ('WebSocket' in window) {
                Chat.socket = new WebSocket(host);
            } else if ('MozWebSocket' in window) {
                Chat.socket = new MozWebSocket(host);
            } else {
                Console.log('Error: WebSocket is not supported by this browser.');
                return;
            }

            Chat.socket.onopen = function () {
                Console.log('Info: WebSocket connection opened.');
                document.getElementById('chat').onkeydown = function(event) {
                    if (event.keyCode == 13) {
                        Chat.sendMessage();
                    }
                };
            };

            Chat.socket.onclose = function () {
                document.getElementById('chat').onkeydown = null;
                Console.log('Info: WebSocket closed.');
            };

            Chat.socket.onmessage = function (message) {
                Console.log(message.data);
            };
        });

        Chat.initialize = function() {
            if (window.location.protocol == 'http:') {
                Chat.connect("ws://localhost:8080/Mybatis/echo");
            } else {
                Chat.connect("wss://localhost:8080/Mybatis/echo");
            }
        };

        Chat.sendMessage = (function() {
            var message = document.getElementById('chat').value;
            if (message != '') {
                Chat.socket.send(message);
                document.getElementById('chat').value = '';
            }
        });

        var Console = {};

        Console.log = (function(message) {
            var console = document.getElementById('console');
            var p = document.createElement('p');
            p.style.wordWrap = 'break-word';
            p.innerHTML = message;
            console.appendChild(p);
            while (console.childNodes.length > 25) {
                console.removeChild(console.firstChild);
            }
            console.scrollTop = console.scrollHeight;
        });

        Chat.initialize();

    </script>
</head>
<body>
<noscript><h2 style="color: #ff0000">Seems your browser doesn't support Javascript! Websockets rely on Javascript being enabled. Please enable
    Javascript and reload this page!</h2></noscript>
<div>
    <p>
        <input type="text" placeholder="type and press enter to chat" id="chat">
    </p>
    <div id="console-container">
        <div id="console"></div>
    </div>
</div>
</body>
</html>
最终效果图

相关文章

网友评论

    本文标题:最简单的java websocket demo

    本文链接:https://www.haomeiwen.com/subject/fsryvttx.html