SpringWebSockets 不从服务器发送消息

Question

您好，我对 spring websockets 有疑问，这是场景：

一个独立的应用程序正在发送（远程）一些数据，例如日期、过程字符串和权重 BigDecimal，这些数据通过 TCP 发送到套接字，

在此数据保存到数据库之后一切都很好，但在下一步（websocket）中，我无法在网页中显示此信息，必须在屏幕上显示（实时）重量数据

这是我的 websocket 配置：

import java.util.List;
import org.springframework.context.annotation.Configuration;
import org.springframework.messaging.converter.MessageConverter;
import org.springframework.messaging.handler.invocation.HandlerMethodArgumentResolver;
import org.springframework.messaging.handler.invocation.HandlerMethodReturnValueHandler;
import org.springframework.messaging.simp.config.ChannelRegistration;
import org.springframework.messaging.simp.config.MessageBrokerRegistry;
import org.springframework.web.socket.config.annotation.EnableWebSocketMessageBroker;
import org.springframework.web.socket.config.annotation.StompEndpointRegistry;
import org.springframework.web.socket.config.annotation.WebSocketMessageBrokerConfigurer;
import org.springframework.web.socket.config.annotation.WebSocketTransportRegistration;

@Configuration
@EnableWebSocketMessageBroker
public class WebSocketConfiguration implements WebSocketMessageBrokerConfigurer {

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

    @Override
    public void configureClientInboundChannel(final ChannelRegistration registration) {
    }

    @Override
    public void configureClientOutboundChannel(final ChannelRegistration registration) {
    }

    @Override
    public void configureMessageBroker(final MessageBrokerRegistry registry) {

    }

    @Override
    public void configureWebSocketTransport(WebSocketTransportRegistration wstr) {

    }

    @Override
    public void addArgumentResolvers(List<HandlerMethodArgumentResolver> list) {

    }

    @Override
    public void addReturnValueHandlers(List<HandlerMethodReturnValueHandler> list) {

    }

    @Override
    public boolean configureMessageConverters(List<MessageConverter> list) {
        return Boolean.TRUE;
    }

}

这是我的另一个类，它接收来自套接字的数据并处理信息并发送到 websocket：

import com.mcss.mcontrols.helper.ByteHelper;
import com.spc.basweb.Constants;
import com.spc.basweb.transmissor.dto.Transmission;
import org.apache.log4j.Logger;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.ApplicationListener;
import org.springframework.messaging.core.MessageSendingOperations;
import org.springframework.messaging.simp.broker.BrokerAvailabilityEvent;
import com.spc.basweb.service.BroadcastingService;
import com.spc.basweb.service.DataProcessorService;
import java.io.IOException;
import org.springframework.integration.annotation.MessageEndpoint;
import org.springframework.integration.annotation.ServiceActivator;
import org.springframework.integration.annotation.Transformer;

@MessageEndpoint
public class BroadcastingServiceImpl implements BroadcastingService, ApplicationListener<BrokerAvailabilityEvent> {

    private static final Logger LOGGER = Logger.getLogger(BroadcastingServiceImpl.class);
    private final MessageSendingOperations<String> messagingTemplate;
    private String processedData;

    @Autowired
    DataProcessorService dataProcessorService;

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

    @Override
    public String getProcessedData() {
        return processedData;
    }

    @Override
    @ServiceActivator(inputChannel = "broadcaster")
    public String broadcast(byte[] bytes) {
        try {
            Transmission t = (Transmission) ByteHelper.toObject(bytes);
            LOGGER.debug(t.getProcedence() + " " + t.getDate() + " " + t.getWeight());
            String rm = this.dataProcessorService.processData(t);
            this.messagingTemplate.convertAndSend(Constants.END_POINT_READ, this.dataProcessorService.getWeighing().getWeight().toString());
            return rm;
        } catch (IOException | ClassNotFoundException ex) {
            LOGGER.error("Error de transmision de objetos", ex);
        }
        return DataProcessorService.NOT_OK_RESPONSE;
    }

    @Override
    public void onApplicationEvent(BrokerAvailabilityEvent e) {
        LOGGER.debug("Application event");
    }

    @Transformer(outputChannel = "broadcaster")
    public String convert(String response) {
        return response;
    }
}

在调试器中我得到了这个信息：

30-03-2016 15:07:20 DEBUG SimpleBrokerMessageHandler:277 - Processing MESSAGE destination=/read session=null payload=3003

在另一个类（控制器）中，我使用相同的方法：

this.messagingTemplate.convertAndSend(Constants.END_POINT_READ, "3500");

并“手动”发送正确显示的信息。我正在调试器中收到这条消息：

30-03-2016 15:05:18 DEBUG SimpleBrokerMessageHandler:277 - Processing MESSAGE destination=/read session=dfR45V77 payload=3500

不同之处在于会话值，但我不知道此会话在此过程中有什么为 null，我做错了什么欢迎澄清或帮助

Answer 1

首先我没有看到configureMessageBroker 的实现，所以根本不清楚它是如何工作的......

另一方面，如果您看到这样的差异，请尝试调试SimpMessagingTemplate 中的代码。

我只在SimpleBrokerMessageHandler 中看到headerAccessor.setSessionId(sessionId);

 logger.debug("Broadcasting to " + subscriptions.size() + " sessions.");