Error opening websocket connection using spring 4

问题

I am trying to create a websocket using this tutorial. Everything is good except that when I try to open websocket connection I get the following error on my browser console and nothing happens at all. Please help me out.

Error:

Opening web socket...
GET http://localhost:8080/hello/info?t=1445510124841 404 (Not Found)
Whoops! Lost connection to http://localhost:8080/hello

TestController.java

package com.test.controller;

import java.util.Set;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.messaging.handler.annotation.MessageMapping;
import org.springframework.messaging.handler.annotation.SendTo;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.servlet.ModelAndView;

import com.test.dto.EmployeeDTO;
import com.test.dto.Greeting;
import com.test.dto.HelloMessage;
import com.test.service.EmployeeService;

@Controller
public class TestController {

    @MessageMapping("/hello")
    @SendTo("/topic/greetings")
    public Greeting greeting(HelloMessage message) throws Exception {
        Thread.sleep(3000); // simulated delay
        System.out.println(message.getName());
        return new Greeting("Hello, " + message.getName() + "!");
    }

    @RequestMapping(value = "/", method = RequestMethod.GET)
    public ModelAndView home(HttpServletRequest request, HttpServletResponse response){
        return new ModelAndView("test");
    }

}

WebSocketConfig.java

package com.test.websocket;

import org.springframework.context.annotation.Configuration;
import org.springframework.messaging.simp.config.MessageBrokerRegistry;
import org.springframework.web.socket.config.annotation.AbstractWebSocketMessageBrokerConfigurer;
import org.springframework.web.socket.config.annotation.EnableWebSocketMessageBroker;
import org.springframework.web.socket.config.annotation.StompEndpointRegistry;

@Configuration
@EnableWebSocketMessageBroker
public class WebSocketConfig  extends AbstractWebSocketMessageBrokerConfigurer{

    @Override
    public void configureMessageBroker(MessageBrokerRegistry config) {
        config.enableSimpleBroker("/topic");
        config.setApplicationDestinationPrefixes("/app");
    }

    @Override
    public void registerStompEndpoints(StompEndpointRegistry registry) {
        // TODO Auto-generated method stub
        registry.addEndpoint("/hello").withSockJS();
    }

}

Test.jsp

<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<!DOCTYPE html>
<html>
<head>
    <title>Hello WebSocket</title>
    <script src="${pageContext.servletContext.contextPath}/js/sockjs-0.3.4.js"></script>
    <script src="${pageContext.servletContext.contextPath}/js/stomp.min.js"></script>
    <script type="text/javascript">
        var stompClient = null;

        function setConnected(connected) {
            document.getElementById('connect').disabled = connected;
            document.getElementById('disconnect').disabled = !connected;
            document.getElementById('conversationDiv').style.visibility = connected ? 'visible' : 'hidden';
            document.getElementById('response').innerHTML = '';
        }

        function connect() {
            var socket = new SockJS('${pageContext.servletContext.contextPath}/hello');
            stompClient = Stomp.over(socket);
            stompClient.connect({}, function(frame) {
                setConnected(true);
                console.log('Connected: ' + frame);
                stompClient.subscribe('/topic/greetings', function(greeting){
                    showGreeting(JSON.parse(greeting.body).content);
                });
            });
        }

        function disconnect() {
            stompClient.disconnect();
            setConnected(false);
            console.log("Disconnected");
        }

        function sendName() {
            var name = document.getElementById('name').value;
            stompClient.send('/app/hello', {}, JSON.stringify({ 'name': name }));
        }

        function showGreeting(message) {
            var response = document.getElementById('response');
            var p = document.createElement('p');
            p.style.wordWrap = 'break-word';
            p.appendChild(document.createTextNode(message));
            response.appendChild(p);
        }
    </script>
</head>
<body>
<noscript><h2 style="color: #ff0000">Seems your browser doesn't support Javascript! Websocket relies on Javascript being enabled. Please enable
    Javascript and reload this page!</h2></noscript>
<div>
    <div>
        <button id="connect" onclick="connect();">Connect</button>
        <button id="disconnect" disabled="disabled" onclick="disconnect();">Disconnect</button>
    </div>
    <div id="conversationDiv">
        <label>What is your name?</label><input type="text" id="name" />
        <button id="sendName" onclick="sendName();">Send</button>
        <p id="response"></p>
    </div>
</div>
</body>
</html>

回答1:

The issue has been resolved. I had not added the WebSocket configuration file to component scan package in my spring configuration file and hence no bean for websocket was getting created.

来源：https://stackoverflow.com/questions/33279090/error-opening-websocket-connection-using-spring-4

标签

Spring

websocket

stomp

spring-websocket

sockjs