最近项目中用到了websocket，记录一下注意事项 1.tomcat版本（7.42不支持，7.57支持，检查tomcat lib中是否存在websocket-api.jar） 2.url设置 （ws://localhost:8080/a/websocket）
server端
package websocket;
import java.io.IOException;
import javax.websocket.OnClose;
import javax.websocket.OnMessage;
import javax.websocket.OnOpen;
import javax.websocket.Session;
import javax.websocket.server.ServerEndpoint;
@ServerEndpoint(value = "/websocket")
public class WebSocketTest {
@OnMessage
public void onMessage(String message, Session session)
throws IOException, InterruptedException {
// 1.接收的信息
System.out.println("收到: " + message);
// 2.向客户端发信息
session.getBasicRemote().sendText("开始");
// 3.隔一段时间发一条信息
int sentMessages = 0;
while(sentMessages < 3){
Thread.sleep(1000);
session.getBasicRemote().
sendText("发送topic数据. 测试: "
+ sentMessages);
sentMessages++;
}
// 4.结束发送
session.getBasicRemote().sendText("结束");
}
@OnOpen
public void onOpen () {
System.out.println("连接客户端");
}
@OnClose
public void onClose () {
System.out.println("断开连接");
}
}
前台页面
<!DOCTYPE html>
<html>
<head>
<title> websockets测试</title>
</head>
<body>
<div>
<input type="submit" value="开始" onclick="start()" />
</div>
<div id="messages"></div>
<script type="text/javascript">
//设置URL
var webSocket = new WebSocket('ws://localhost:8080/a/websocket');
webSocket.onerror = function(event) {
onError(event)
};
webSocket.onopen = function(event) {
onOpen(event)
};
webSocket.onmessage = function(event) {
onMessage(event)
};
function onMessage(event) {
document.getElementById('messages').innerHTML
+= '<br />' + event.data;
}
function onOpen(event) {
document.getElementById('messages').innerHTML
= '连接已建立';
}
function onError(event) {
alert(event.data);
alert("error");
}
//向服务器发送信息
function start() {
webSocket.send('订阅topic');
return false;
}
</script>
</body>
</html>
效果图
时间： 2024-07-30 08:38:22