Question

我使用 Spring 4 通过 WebSockets 开发实时通知系统。

源代码如下：

WebSocketConfig：

@Configuration
@EnableScheduling
@EnableWebSocketMessageBroker
public class WebSocketConfig extends AbstractWebSocketMessageBrokerConfigurer {

    @Override
    public void registerStompEndpoints(StompEndpointRegistry registry) {
        registry.addEndpoint("/lrt").withSockJS();
    }

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

}

LRTStatusListener：

@Service
public class LRTStatusListener implements ApplicationListener<BrokerAvailabilityEvent>{

    private static final Logger LOG = LoggerFactory.getLogger(LRTStatusListener.class);
    private final static long LRT_ID = 1234567890;
    private final static String LRT_OWNER = "Walter White";
    private final LRTStatusGenerator lrtStatusGenerator = new LRTStatusGenerator(LRT_ID, LRT_OWNER);
    private final MessageSendingOperations<String> messagingTemplate;
    private AtomicBoolean brokerAvailable = new AtomicBoolean();

    @Autowired
    public LRTStatusListener(MessageSendingOperations<String> messagingTemplate) {
        this.messagingTemplate = messagingTemplate;
    }

    @Override
    public void onApplicationEvent(BrokerAvailabilityEvent event) {
        this.brokerAvailable.set(event.isBrokerAvailable());
    }

    @Scheduled(fixedDelay=2000)
    public void sendLRTStatus() {
        LRTStatus lrtStatus = this.lrtStatusGenerator.generateLRTStatus();
        if (LOG.isTraceEnabled())
            LOG.trace("Sending LRT status");
        if (this.brokerAvailable.get())
            this.messagingTemplate
                .convertAndSend("/topic/status" + lrtStatus.getLRTId(), lrtStatus);
    }

    // Random status generator
    private static class LRTStatusGenerator {

        private LRTStatus lrtStatus;

        public LRTStatusGenerator(long lrtId, String owner) {
            lrtStatus = new LRTStatus(lrtId, owner, getCurrentTimestamp(), generateLRTStatusMessage());
        }

        public LRTStatus generateLRTStatus() {
            lrtStatus.setMessage(generateLRTStatusMessage());
            return lrtStatus;
        }

        private String getCurrentTimestamp() {
            Date date = new Date();
            Timestamp timestamp = new Timestamp(date.getTime());
            return timestamp.toString();
        }

        private String generateLRTStatusMessage() {
            String statusMessage;
            switch ((int) Math.random() * 2) {
            case 1:
                statusMessage =
                        "HANK: What? You want me to beg? You're the smartest guy I ever met. " +
                        "And you're too stupid to see... he made up his mind ten minutes ago.";
                break;
            case 2:
                statusMessage =
                        "WALTER: That's right. Now say my name. " +
                        "- DECLAN: ...You're Heisenberg. - WALTER: You're goddamn right.";
                break;
            default:
                statusMessage =
                        "WALTER: I am not in danger, Skyler. I am the danger! " +
                        "A guy opens his door and gets shot and you think that of me? " +
                        "No. I am the one who knocks!";
                break;
            }
            return statusMessage;
        }

    }

}

CheckLRTStatusController

@Controller
public class CheckLRTStatusController {

    @MessageExceptionHandler
    @SendToUser("/topic/errors")
    public String handleException(Throwable exception) {
        return exception.getMessage();
    }

}

应用程序通过每2000毫秒更改一次信息来模拟长时间运行事务（LRT）的状态。

现在，我通过 SockJS 定义客户端来测试WebSocket：

<script src="http://cdn.sockjs.org/sockjs-0.3.min.js"></script>
<script>
    var sock = new SockJS('/lrt');
    sock.onopen = function() {
        console.log('open');
    };
    sock.onmessage = function(e) {
        console.log('message', e.data);
    };
    sock.onclose = function() {
        console.log('close');
    };
</script>

连接正常，但我无法看到数据流。

如何正确配置我的应用程序，以便在我的客户端控制台上生成然后路由WebSocket服务器发送的消息？

请注意，我还使用内置 Message Broker ，目的是管理邮件队列。

Answer 1

这是您目前唯一的JavaScript代码吗？：

<script src="http://cdn.sockjs.org/sockjs-0.3.min.js"></script>
<script>
    var sock = new SockJS('/lrt');
    sock.onopen = function() {
        console.log('open');
    };
    sock.onmessage = function(e) {
        console.log('message', e.data);
    };
    sock.onclose = function() {
        console.log('close');
    };
</script>

仅在SockJS上建立与回退的连接，但您没有订阅消息代理。你也需要这样做。

在您当前的设置中，您有：

registry.enableSimpleBroker("/queue/", "/topic/");

您需要创建一个JavaScript STOMP客户端（通过SockJS）订阅这些客户端，例如：

stompClient.subscribe("/topic/status*", function(message) {
    ...
});

stompClient.subscribe("/queue/whatever", function(message) {
    ...
});

查看spring-websocket-portfolio应用程序以获取完整的工作示例。

在Spring 4中配置WebSocket服务器

1 个答案: