Spring.io websocket example seems to be wrong

2020-04-01 java spring spring-boot websocket spring-websocket

I downloaded the websocket example from spring.io, and opened it up in my IDE.

I've been trying run it normally, and also with maven, which both leads to the following results:

I'm getting these errors in the browsers console:

enter image description here

And this error in the servers console:

2020-03-31 17:33:56.518 ERROR 13456 --- [nio-8080-exec-7] s.e.ErrorMvcAutoConfiguration$StaticView : Cannot render error page for request [/gs-guide-websocket/438/baxesosu/htmlfile] and exception [An existing connection was forcibly closed by the remote host] as the response has already been committed. As a result, the response may have the wrong status code.

Sources

GreetingController.java

    @Controller
    public class GreetingController {


        @MessageMapping("/hello")
        @SendTo("/topic/greetings")
        public Greeting greeting(HelloMessage message) throws Exception {
            Thread.sleep(1000); // simulated delay
            return new Greeting("Hello, " + HtmlUtils.htmlEscape(message.getName()) + "!");
        }
    }

WebSocketConfig.java

@Configuration
@EnableWebSocketMessageBroker
public class WebSocketConfig implements WebSocketMessageBrokerConfigurer {

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

    @Override
    public void registerStompEndpoints(StompEndpointRegistry registry) {
        registry.addEndpoint("/gs-guide-websocket").withSockJS().setClientLibraryUrl("/webjars/sockjs-client/1.0.2/sockjs.min.js");
    }

}

app.js

var stompClient = null;

function setConnected(connected) {
    $("#connect").prop("disabled", connected);
    $("#disconnect").prop("disabled", !connected);
    if (connected) {
        $("#conversation").show();
    }
    else {
        $("#conversation").hide();
    }
    $("#greetings").html("");
}

function connect() {
    var socket = new SockJS('/gs-guide-websocket');
    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() {
    if (stompClient !== null) {
        stompClient.disconnect();
    }
    setConnected(false);
    console.log("Disconnected");
}

function sendName() {
    stompClient.send("/app/hello", {}, JSON.stringify({'name': $("#name").val()}));
}

function showGreeting(message) {
    $("#greetings").append("<tr><td>" + message + "</td></tr>");
}

$(function () {
    $("form").on('submit', function (e) {
        e.preventDefault();
    });
    $( "#connect" ).click(function() { connect(); });
    $( "#disconnect" ).click(function() { disconnect(); });
    $( "#send" ).click(function() { sendName(); });
});

index.html

<!DOCTYPE html>
<html>
<head>
    <title>Hello WebSocket</title>
    <link href="/webjars/bootstrap/css/bootstrap.min.css" rel="stylesheet">
    <link href="/main.css" rel="stylesheet">
    <script src="/webjars/jquery/jquery.min.js"></script>
    <script src="/webjars/sockjs-client/sockjs.min.js"></script>
    <script src="/webjars/stomp-websocket/stomp.min.js"></script>
    <script src="/app.js"></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 id="main-content" class="container">
    <div class="row">
        <div class="col-md-6">
            <form class="form-inline">
                <div class="form-group">
                    <label for="connect">WebSocket connection:</label>
                    <button id="connect" class="btn btn-default" type="submit">Connect</button>
                    <button id="disconnect" class="btn btn-default" type="submit" disabled="disabled">Disconnect
                    </button>
                </div>
            </form>
        </div>
        <div class="col-md-6">
            <form class="form-inline">
                <div class="form-group">
                    <label for="name">What is your name?</label>
                    <input type="text" id="name" class="form-control" placeholder="Your name here...">
                </div>
                <button id="send" class="btn btn-default" type="submit">Send</button>
            </form>
        </div>
    </div>
    <div class="row">
        <div class="col-md-12">
            <table id="conversation" class="table table-striped">
                <thead>
                <tr>
                    <th>Greetings</th>
                </tr>
                </thead>
                <tbody id="greetings">
                </tbody>
            </table>
        </div>
    </div>
</div>
</body>
</html>

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.2.2.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>messaging-stomp-websocket</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>messaging-stomp-websocket</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-websocket</artifactId>
        </dependency>
        <dependency>
            <groupId>org.webjars</groupId>
            <artifactId>webjars-locator-core</artifactId>
        </dependency>
        <dependency>
            <groupId>org.webjars</groupId>
            <artifactId>sockjs-client</artifactId>
            <version>1.0.2</version>
        </dependency>
        <dependency>
            <groupId>org.webjars</groupId>
            <artifactId>stomp-websocket</artifactId>
            <version>2.3.3</version>
        </dependency>
        <dependency>
            <groupId>org.webjars</groupId>
            <artifactId>bootstrap</artifactId>
            <version>3.3.7</version>
        </dependency>
        <dependency>
            <groupId>org.webjars</groupId>
            <artifactId>jquery</artifactId>
            <version>3.1.1-1</version>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>

Answers

Related