问题
Socket长连接建立连接报错 WebSocket connection to ‘ws://localhost:8080/bms/chat/1’ failed:
详细问题
笔者使用技术框架Servlet + JSP，基于Socket长连接实现实时聊天室
JSP核心代码
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%@ taglib prefix="fn" uri="http://java.sun.com/jsp/jstl/functions" %>
<html>
<head>
<title>实时聊天室</title>
<script>
<c:set var="chatObjectId" value="${chatObjectId}"/>
var socket;
function connect() {
socket = new WebSocket("ws://localhost:8080/bms/chat?chatObjectId=" + ${
ChatObjectId});
socket.onopen = function () {
console.log("WebSocket连接已打开");
};
socket.onmessage = function (event) {
var message = event.data;
// 处理接收到的消息，例如将其显示在聊天窗口中
var chatWindow = document.getElementById("chat-window");
var newMessage = document.createElement("p");
newMessage.textContent = message;
chatWindow.appendChild(newMessage);
};
}
function sendMessage() {
var input = document.getElementById("message");
var message = input.value;
socket.send(message);
input.value = "";
}
function disconnect() {
socket.close();
}
</script>
</head>
<body>
<div id="chat-window"></div>
<input type="text" id="message" />
<button onclick="sendMessage()">发送</button>
<button onclick="connect()">连接</button>
<button onclick="disconnect()">断开连接</button>
</body>
</html>
java核心代码
import javax.websocket.*;
import javax.websocket.server.ServerEndpoint;
import java.io.IOException;
import java.util.Collections;
import java.util.HashSet;
import java.util.Set;
@ServerEndpoint("/chat")
public class ChatServer {
private static Set<Session> sessions = Collections.synchronizedSet(new HashSet<>());
private static Map<Integer, Session> userSessions = Collections.synchronizedMap(new HashMap<>());
@OnOpen
public void onOpen(Session session, @PathParam("ChatObjectId") String ChatObjectId) {
sessions.add(session);
// 将字符串转换为整数类型的用户ID
Integer ChatObjectId= Integer.parseInt(ChatObjectId);
// 将会话与userId关联，并添加到userSessions集合中
userSessions.put(ChatObjectId, session);
}
@OnMessage
public void onMessage(String message, Session session) throws IOException {
try {
Jsonb jsonb = JsonbBuilder.create();
MessagePayload payload = jsonb.fromJson(message, MessagePayload.class);
Integer targetUserId = payload.getUserId();
String content = payload.getContent();
sendToUser(targetUserId, content);
} catch (JsonbException e) {
e.printStackTrace();
}
}
public void sendToUser(Integer userId, String message) throws IOException {
Session session = userSessions.get(userId);
if (session != null) {
session.getBasicRemote().sendText(message);
}
}
@OnClose
public void onClose(Session session) {
sessions.remove(session);
}
@OnError
public void onError(Throwable error) {
error.printStackTrace();
}
}
运行项目，游览器控制台报错
WebSocket connection to 'ws://localhost:8080/bms/chat/1' failed
解决方案
对于java代码ChatServer类的注解由
@ServerEndpoint("/chat")
改为
@ServerEndpoint("/chat/{chatObjectId}")
解决原因
@ServerEndpoint注解的值应该与你在JSP中WebSocket连接的URL路径一致。笔者JSP代码中连接的URL路径是ws://localhost:8080/bms/chat?chatObjectId=1，但是笔者Java代码中的@ServerEndpoint注解值为/chat。
因此需要将@ServerEndpoint注解的值改为/chat/{chatObjectId}。这样，URL路径中的chatObjectId将作为路径参数传递给onOpen方法。
笔者误以为只要在onOpen传递参数就可以
参考文献
解决方案参考chatgpt
原创不易
转载请标明出处
如果对你有所帮助 别忘啦点赞支持哈
