com.amazonaws.services.iot.client.shadow.AwsIotDeviceDeltaListener Maven / Gradle / Ivy
/*
* Copyright 2016 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License").
* You may not use this file except in compliance with the License.
* A copy of the License is located at
*
* http://aws.amazon.com/apache2.0
*
* or in the "license" file accompanying this file. This file is distributed
* on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
* express or implied. See the License for the specific language governing
* permissions and limitations under the License.
*/
package com.amazonaws.services.iot.client.shadow;
import java.io.IOException;
import java.util.logging.Logger;
import com.amazonaws.services.iot.client.AWSIotMessage;
import com.amazonaws.services.iot.client.AWSIotQos;
import com.amazonaws.services.iot.client.AWSIotTopic;
import com.fasterxml.jackson.databind.JsonNode;
/**
* This class extends {@link AWSIotTopic} to provide a callback function for
* receiving the shadow delta updates.
*/
public class AwsIotDeviceDeltaListener extends AWSIotTopic {
private static final Logger LOGGER = Logger.getLogger(AwsIotDeviceDeltaListener.class.getName());
private final AbstractAwsIotDevice device;
public AwsIotDeviceDeltaListener(String topic, AWSIotQos qos, AbstractAwsIotDevice device) {
super(topic, qos);
this.device = device;
}
@Override
public void onMessage(AWSIotMessage message) {
String payload = message.getStringPayload();
if (payload == null) {
LOGGER.warning("Received empty delta for device " + device.getThingName());
return;
}
JsonNode rootNode;
try {
rootNode = device.getJsonObjectMapper().readTree(payload);
if (!rootNode.isObject()) {
throw new IOException();
}
} catch (IOException e) {
LOGGER.warning("Received invalid delta for device " + device.getThingName());
return;
}
if (device.enableVersioning) {
JsonNode node = rootNode.get("version");
if (node == null) {
LOGGER.warning("Missing version field in delta for device " + device.getThingName());
return;
}
long receivedVersion = node.longValue();
long localVersion = device.getLocalVersion().get();
if (receivedVersion < localVersion) {
LOGGER.warning("An old version of delta received for " + device.getThingName() + ", local "
+ localVersion + ", received " + receivedVersion);
return;
}
device.getLocalVersion().set(receivedVersion);
LOGGER.info("Local version number updated to " + receivedVersion);
}
JsonNode node = rootNode.get("state");
if (node == null) {
LOGGER.warning("Missing state field in delta for device " + device.getThingName());
return;
}
device.onShadowUpdate(node.toString());
}
@Override
public void onSuccess() {
}
@Override
public void onFailure() {
LOGGER.warning("Failed to subscribe to device topic " + topic);
}
@Override
public void onTimeout() {
LOGGER.warning("Timeout when subscribing to device topic " + topic);
}
}