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
