Data compression-IoT Platform (Deprecated)(IoT)-阿里云帮助中心

Prerequisites

Limits

The data compression feature is available only for Exclusive Enterprise Edition instances and Standard Enterprise Edition instances. For more information, see Purchase an Enterprise instance.

Background information

Some IoT devices rely on cellular networks with high traffic costs. Data compression reduces the size of transmitted data, lowering traffic usage and costs.

For more information about data compression and transmission, see Data compression.

Directly connected devices

Specify topics for compression and decompression

In the following sample code:

compTopicList: topics for server-to-device messages. The server compresses data, and devices decompress data.
decompTopicList: topics for device-to-server messages. Devices compress data, and the server decompresses data. The hit data compression case debugging logs are generated on the devices.

Important

Compression and decompression relationships are stored on the server. To remove them from a topic, you must disable compression and decompression in the device SDK.

If compression and decompression are still enabled on the server and a device connects to IoT Platform with an SDK that does not support data compression, communication issues may occur.
Do not specify the /sys/${productKey}/${deviceName}/thing/dsltemplate/get_reply topic for compTopicList. Otherwise, the device SDK may fail to initialize.
Topics with wildcard characters are not supported for data compression and decompression.

// Specify the topics that are used when the server compresses data and devices decompress data.
String compTopic =  "/" + deviceInfoData.productKey + "/" + deviceInfoData.deviceName + "/user/get";
List<String> compTopicList = new ArrayList<>();
compTopicList.add(compTopic);

// Specify the topics that are used when devices compress data and the server decompresses data.
String decompTopic = "/sys/" + deviceInfoData.productKey + "/" + deviceInfoData.deviceName + "/thing/event/property/post";
List<String> decompTopicList = new ArrayList<>();
decompTopicList.add(decompTopic);

ICompressor compressor = LinkKit.getInstance().getCompressor();
compressor.setCompressTopics(compTopicList, decompTopicList, new IConnectSendListener() {
    @Override
    public void onResponse(ARequest aRequest, AResponse aResponse) {

        // Configure the custom business logic, such as property reporting.
    }

    @Override
    public void onFailure(ARequest aRequest, AError aError) {

    }
});

Important

In the setCompressTopics method:

The first parameter specifies topics for server-to-device compression. The value can be null.
The second parameter specifies topics for device-to-server compression. The value can be null.

Disable compression and decompression

ICompressor compressor = LinkKit.getInstance().getCompressor();
compressor.setCompressTopics(null, null, new IConnectSendListener() {
    @Override
    public void onResponse(ARequest aRequest, AResponse aResponse) {

        //TODO: your logic
    }

    @Override
    public void onFailure(ARequest aRequest, AError aError) {

    }
});

Gateways and sub-devices

Specify topics for compression and decompression

In the following sample code:

compTopicList: topics for server-to-device messages. The server compresses data, and devices decompress data.
decompTopicList: topics for device-to-server messages. Devices compress data, and the server decompresses data. The hit data compression case debugging logs are generated on the devices.

Important

Compression and decompression relationships are stored on the server. To remove them from a topic, you must disable compression and decompression in the device SDK.

If compression and decompression are still enabled on the server and a device connects to IoT Platform with an SDK that does not support data compression, communication issues may occur.
Topics with wildcard characters are not supported for data compression and decompression.
A gateway and its sub-devices cannot use compression and decompression at the same time.

// Compress data only after the sub-device connects to IoT Platform.
final DeviceInfo info = new DeviceInfo(); 
// Set the info parameter to the description of a sub-device that is connected to IoT Platform.
// info = userSubDev.get(index);

// Specify the topics that are used when the server compresses data and devices decompress data.
String compTopic =  "/" + info.productKey + "/" + info.deviceName + "/user/get";
List<String> compTopicList = new ArrayList<>();
compTopicList.add(compTopic);

// Specify the topics that are used when devices compress data and the server decompresses data.
String decompTopic = "/sys/" + info.productKey + "/" + info.deviceName + "/thing/event/property/post";
List<String> decompTopicList = new ArrayList<>();
decompTopicList.add(decompTopic);
String detopic2 = "/" + info.productKey + "/" + info.deviceName + "/user/update";
decompTopicList.add(detopic2);

LinkKit.getInstance().getGateway().gatewaySubDeviceSetCompressTopics(info, compTopicList, decompTopicList, new ISubDeviceActionListener() {
    @Override
    public void onSuccess() {
        // Specify the messages that the sub-device submits to IoT Platform, such as device properties.
    }

    @Override
    public void onFailed(AError aError) {

    }
});

Disable compression and decompression

LinkKit.getInstance().getGateway().gatewaySubDeviceSetCompressTopics(info, null, null, new ISubDeviceActionListener() {
    @Override
    public void onSuccess() {
        // Specify the messages that the sub-device submits to IoT Platform, such as device properties.
    }

    @Override
    public void onFailed(AError aError) {

    }
});