Use UpdateThingShadow with an AWS SDK or CLI

//! Update the shadow of an AWS IoT thing.
/*!
  \param thingName: The name for the thing.
  \param document: The state information, in JSON format.
  \param clientConfiguration: AWS client configuration.
  \return bool: Function succeeded.
 */
bool AwsDoc::IoT::updateThingShadow(const Aws::String &thingName,
                                    const Aws::String &document,
                                    const Aws::Client::ClientConfiguration &clientConfiguration) {
    Aws::IoTDataPlane::IoTDataPlaneClient iotDataPlaneClient(clientConfiguration);
    Aws::IoTDataPlane::Model::UpdateThingShadowRequest updateThingShadowRequest;
    updateThingShadowRequest.SetThingName(thingName);
    std::shared_ptr<std::stringstream> streamBuf = std::make_shared<std::stringstream>(
            document);
    updateThingShadowRequest.SetBody(streamBuf);
    Aws::IoTDataPlane::Model::UpdateThingShadowOutcome outcome = iotDataPlaneClient.UpdateThingShadow(
            updateThingShadowRequest);
    if (outcome.IsSuccess()) {
        std::cout << "Successfully updated thing shadow." << std::endl;
    }
    else {
        std::cerr << "Error while updating thing shadow."
                  << outcome.GetError().GetMessage() << std::endl;
    }

    return outcome.IsSuccess();
}

To update a thing shadow

The following update-thing-shadow example modifies the current state of the device shadow for the specified thing and saves it to the file output.txt.

aws iot-data update-thing-shadow \
    --thing-name MyRPi \
    --payload "{"state":{"reported":{"moisture":"okay"}}}" \
    "output.txt"

The command produces no output on the display, but the following shows the contents of output.txt:

{
    "state": {
        "reported": {
            "moisture": "okay"
        }
    },
    "metadata": {
        "reported": {
            "moisture": {
                "timestamp": 1560270036
            }
        }
    },
    "version": 2,
    "timestamp": 1560270036
}

For more information, see Device Shadow Service Data Flow in the AWS IoT Developers Guide.

    /**
     * Updates the shadow of an IoT Thing asynchronously.
     *
     * @param thingName The name of the IoT Thing.
     *
     * This method initiates an asynchronous request to update the shadow of an IoT Thing.
     * If the request is successful, it prints a confirmation message.
     * If an exception occurs, it prints the error message.
     */
    public void updateShadowThing(String thingName) {
        // Create Thing Shadow State Document.
        String stateDocument = "{\"state\":{\"reported\":{\"temperature\":25, \"humidity\":50}}}";
        SdkBytes data = SdkBytes.fromString(stateDocument, StandardCharsets.UTF_8);
        UpdateThingShadowRequest updateThingShadowRequest = UpdateThingShadowRequest.builder()
            .thingName(thingName)
            .payload(data)
            .build();

        CompletableFuture<UpdateThingShadowResponse> future = getAsyncDataPlaneClient().updateThingShadow(updateThingShadowRequest);
        future.whenComplete((updateResponse, ex) -> {
            if (updateResponse != null) {
                System.out.println("Thing Shadow updated successfully.");
            } else {
                Throwable cause = ex != null ? ex.getCause() : null;
                if (cause instanceof IotException) {
                    System.err.println(((IotException) cause).awsErrorDetails().errorMessage());
                } else if (cause != null) {
                    System.err.println("Unexpected error: " + cause.getMessage());
                } else {
                    System.err.println("Failed to update Thing Shadow.");
                }
            }
        });

        future.join();
    }

suspend fun updateShawdowThing(thingNameVal: String?) {
    // Create the thing shadow state document.
    val stateDocument = "{\"state\":{\"reported\":{\"temperature\":25, \"humidity\":50}}}"
    val byteStream: ByteStream = ByteStream.fromString(stateDocument)
    val byteArray: ByteArray = byteStream.toByteArray()

    val updateThingShadowRequest =
        UpdateThingShadowRequest {
            thingName = thingNameVal
            payload = byteArray
        }

    IotDataPlaneClient { region = "us-east-1" }.use { iotPlaneClient ->
        iotPlaneClient.updateThingShadow(updateThingShadowRequest)
        println("The thing shadow was updated successfully.")
    }
}