Github user KayLerch commented on a diff in the pull request: https://github.com/apache/nifi/pull/349#discussion_r65422534 --- Diff: nifi-nar-bundles/nifi-aws-bundle/nifi-aws-processors/src/main/java/org/apache/nifi/processors/aws/iot/PutAWSIoT.java --- @@ -0,0 +1,141 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You under the Apache License, Version 2.0 + * (the "License"); you may not use this file except in compliance with + * the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License 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 org.apache.nifi.processors.aws.iot; + +import org.apache.nifi.annotation.behavior.InputRequirement; +import org.apache.nifi.annotation.behavior.ReadsAttribute; +import org.apache.nifi.annotation.behavior.ReadsAttributes; +import org.apache.nifi.annotation.behavior.WritesAttributes; +import org.apache.nifi.annotation.behavior.WritesAttribute; +import org.apache.nifi.annotation.documentation.CapabilityDescription; +import org.apache.nifi.annotation.documentation.SeeAlso; +import org.apache.nifi.annotation.documentation.Tags; +import org.apache.nifi.annotation.lifecycle.OnScheduled; +import org.apache.nifi.components.PropertyDescriptor; +import org.apache.nifi.flowfile.FlowFile; +import org.apache.nifi.processor.ProcessContext; +import org.apache.nifi.processor.ProcessSession; +import org.apache.nifi.processor.Relationship; +import org.apache.nifi.processor.util.StandardValidators; +import org.eclipse.paho.client.mqttv3.MqttException; + +import java.io.ByteArrayOutputStream; +import java.util.Arrays; +import java.util.Collections; +import java.util.List; +import java.util.Set; +import java.util.Map; + +@Tags({"Amazon", "AWS", "IOT", "MQTT", "Websockets", "Put", "Publish", "Send"}) +@InputRequirement(InputRequirement.Requirement.INPUT_REQUIRED) +@CapabilityDescription("Publishes messages to MQTT-topic(s) of AWS IoT. The processor keeps open a WebSocket connection and will automatically renew the " + + "connection to overcome Amazon's service limit on maximum connection duration. Most of the " + + "configuration can be overridden by values coming in as message attributes. This applies for " + + "the topic (corresponding message attribute is \"aws.iot.mqtt.topic.override\"), the qos-level " + + "(\"aws.iot.mqtt.qos.override\") and the retention (\"aws.iot.mqtt.retained.override\")") +@SeeAlso({ PutAWSIoTShadow.class }) +@ReadsAttributes({ + @ReadsAttribute(attribute = "aws.iot.mqtt.topic.override", description = "Overrides the processor configuration for topic."), + @ReadsAttribute(attribute = "aws.iot.mqtt.qos.override", description = "Overrides the processor configuration for quality of service."), + @ReadsAttribute(attribute = "aws.iot.mqtt.retained.override", description = "Overrides the processor configuration for retaining a published state in the AWS shadow.") +}) +@WritesAttributes({ + @WritesAttribute(attribute = "aws.iot.mqtt.exception", description = "Error details") +}) +public class PutAWSIoT extends AbstractAWSIoTProcessor { + private final static String PROP_NAME_RETAINED = "aws.iot.mqtt.retained"; + private final static String ATTR_NAME_TOPIC = PROP_NAME_TOPIC + ".override"; + private final static String ATTR_NAME_QOS = PROP_NAME_QOS + ".override"; + private final static String ATTR_NAME_RETAINED = PROP_NAME_RETAINED + ".override"; + private final static String ATTR_NAME_EXCEPTION = "aws.iot.mqtt.exception"; + private final static Boolean PROP_DEFAULT_RETAINED = false; + private Boolean shouldRetain; + + public static final PropertyDescriptor PROP_RETAINED = new PropertyDescriptor + .Builder().name(PROP_NAME_RETAINED) + .description("For messages being published, a true setting indicates that the MQTT server " + + "should retain a copy of the message. The message will then be transmitted to new " + + "subscribers to a topic that matches the message topic. For subscribers registering " + + "a new subscription, the flag being true indicates that the received message is not " + + "a new one, but one that has been retained by the MQTT server.") + .required(true) + .defaultValue(PROP_DEFAULT_RETAINED.toString()) + .addValidator(StandardValidators.BOOLEAN_VALIDATOR) + .build(); + + public static final List<PropertyDescriptor> properties = Collections.unmodifiableList( + Arrays.asList( + PROP_QOS, + PROP_TOPIC, + PROP_RETAINED, + PROP_ENDPOINT, + PROP_KEEPALIVE, + PROP_CLIENT, + AWS_CREDENTIALS_PROVIDER_SERVICE, + TIMEOUT, + REGION)); + + @Override + protected List<PropertyDescriptor> getSupportedPropertyDescriptors() { + return properties; + } + + @Override + public Set<Relationship> getRelationships() { + return Collections.singleton(REL_SUCCESS); + } + + @OnScheduled + public void onScheduled(final ProcessContext context) { + shouldRetain = context.getProperty(PROP_RETAINED).isSet() ? context.getProperty(PROP_RETAINED).asBoolean() : PROP_DEFAULT_RETAINED; + init(context); + } + + @Override + public void onTrigger(final ProcessContext context, final ProcessSession session) { + // check if MQTT-connection is about to expire + if (isConnectionAboutToExpire()) { + // renew connection + mqttClient = connect(context); + } + // get flowfile + FlowFile flowFile = session.get(); + if (flowFile == null) { + return; + } + Map<String, String> attributes = flowFile.getAttributes(); + // if provided override MQTT configuration with values from the corresponding message attributes + String topic = attributes.containsKey(ATTR_NAME_TOPIC) ? attributes.get(ATTR_NAME_TOPIC) : awsTopic; + Integer qos = attributes.containsKey(ATTR_NAME_QOS) ? Integer.parseInt(attributes.get(ATTR_NAME_QOS)) : awsQos; + Boolean retained = attributes.containsKey(ATTR_NAME_RETAINED) ? Boolean.parseBoolean(attributes.get(ATTR_NAME_RETAINED)) : shouldRetain; + // get message content + final ByteArrayOutputStream fileContentStream = new ByteArrayOutputStream(); + session.exportTo(flowFile, fileContentStream); + + try { + // publish messages to mqtt-topic(s) + mqttClient.publish(topic, fileContentStream.toByteArray(), qos, retained); + session.transfer(flowFile, REL_SUCCESS); + session.getProvenanceReporter().send(flowFile, awsEndpoint + "(" + awsClientId + ")"); + } catch (MqttException e) { + getLogger().error("Error while initially subscribing to topics with client " + mqttClient.getClientId() + " caused by " + e.getMessage()); --- End diff -- collateral damage of pasting code ;) changed it.
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