Question

关于实时通知的问题..

Post: https://xxxiot.cumulocity.com/cep/realtime
Body: 
[
 { 
  "channel": "/meta/handshake",
  "version": "1.0",
  "mininumVersion": "1.0beta",
  "supportedConnectionTypes": ["long-polling","callback-polling"],
  "advice":{"timeout":120000,"interval":30000}
 }
]

我的回复：

[
 {
  "minimumVersion": "1.0",
  "supportedConnectionTypes": [
  "smartrest-long-polling",
  "long-polling"
],
  "successful": true,
  "channel": "/meta/handshake",
  "ext": {
  "ack": true
},
 "clientId": "5o0ghvle7yy4ix41on423v6k3j87",
 "version": "1.0"
}

收到clientId后..我运行了以下命令：

Post: https://xxxiot.cumulocity.com/cep/realtime
Body:
[
 {
  "channel": "/meta/subscribe",
  "clientId": "5o0ghvle7yy4ix41on423v6k3j87",
  "subscription": "/alarms/overHeatAlarms"
 }
]

响应：

[
 {
 "error": "403:denied_by_security_policy:create_denied",
 "subscription": "/alarms/overHeatAlarms",
 "successful": false,
 "channel": "/meta/subscribe"
 }
]

问题出在哪里？我正试图订阅“过热警报”！它可能不存在？我可以阅读现有信息吗？谢谢， ALIM

Answer 1

是的，你的怀疑是正确的。基本上有两种选择：

订阅特定设备的所有闹钟或闹钟：使用＆＃34; / cep / realtime＆＃34;和频道＆＃34; / alarms / * resp。频道＆＃34; /闹钟/ [设备ID]＆＃34;。
创建一个处理规则，过滤掉过热警报并订阅该规则：使用＆＃34; / cep / notifications＆＃34;和频道＆＃34; / [模块名称] / [声明名称]＆＃34;。

单击＆＃34;新模块＆＃34;时，模块名称是您输入的名称。语句名称是您添加到语句中的名称，例如

@Name('overHeatAlarms')
select * from AlarmsCreated where [your condition for overheat alarms]

（如果你不在那里写一个名字，它们将是name statement_1，statement_2，....）

要从Java获取通知，请查看获取设备更改通知的example。在subscribe（）方法中，您传递＆＃34; *＆＃34;或设备ID。要获取通知，请传递SubscriptionListener的实现，特别是onNotification方法。您可以修改＆＃34; channelPrefix＆＃34; to＆＃34; / alarms /＆＃34;或＆＃34; /测量/＆＃34;获得其他通知。

Answer 2

谢谢，安德烈。我已经测试了以下Code Snippet ..它可以工作，但它不是最好的解决方案： - ）

    MeasurementApi measurementApi = getMeasurementApi();
    MeasurementFilter measurementFilter = new MeasurementFilter();
    while (true) {
        Calendar cal = Calendar.getInstance();

        Date toDate = cal.getTime();
        cal.add(Calendar.SECOND, -25);
        Date fromDate = cal.getTime();
        measurementFilter.byDate(fromDate, toDate);
        measurementFilter.byFragmentType(TemperatureMeasurement.class);
        measurementFilter.bySource(new GId(DEVICE_SIMULATOR));
        MeasurementCollection mc = measurementApi
                .getMeasurementsByFilter(measurementFilter);

        MeasurementCollectionRepresentation measurements = mc.get();
        for (; measurements != null; measurements = mc
                .getNextPage(measurements)) {
            for (MeasurementRepresentation measurement : measurements
                    .getMeasurements()) {
                TemperatureMeasurement temperatureSensor = measurement
                        .get(TemperatureMeasurement.class);

                System.out.println(measurement.getSource().getId() + " "
                        + measurement.getTime()+ " " + temperatureSensor.getTemperature() );

            }
        }
    }

订阅频道/实时通知

2 个答案: