code: public void emit(ComponentInfo componentInfo, EmitInfo info)
      {
          if (this.sessions.size() == 0)
          {
              return;
          }
  
          Date nowTime = new Date();
          DateFormat format = new SimpleDateFormat(DATE_PATTERN);
          String nowTimeStr = format.format(nowTime);
  
          Map<String, Object> objectMap = Maps.newHashMap();
          objectMap.put("time", nowTimeStr);
          objectMap.put("component", componentInfo);
          objectMap.put("emitinfo", info);
  
          String logInfo;
          try
          {
              logInfo = this.mapper.writeValueAsString(objectMap);
          }
          catch (JsonProcessingException ex)
          {
              String msgFormat = "Event convert failed. Skip log output. : ComponentInfo={0}, EmitInfo={1}";
              String message = MessageFormat.format(msgFormat, componentInfo,
                      ToStringBuilder.reflectionToString(info, ToStringStyle.SHORT_PREFIX_STYLE));
              logger.warn(message, ex);
              return;
          }
  
          for (Entry<String, Session> entry : this.sessions.entrySet())
          {
              entry.getValue().getAsyncRemote().sendText(logInfo, this.handler);
          }
      }
docs: Log emit info.
  
  @param componentInfo component info
  @param info emit info