samples/connectors/src/main/java/org/apache/edgent/samples/connectors/mqtt/PublisherApp.java

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to you under the Apache License, Version 2.0 (the
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package org.apache.edgent.samples.connectors.mqtt;

import static org.apache.edgent.samples.connectors.mqtt.MqttClient.OPT_PUB_CNT;
import static org.apache.edgent.samples.connectors.mqtt.MqttClient.OPT_QOS;
import static org.apache.edgent.samples.connectors.mqtt.MqttClient.OPT_RETAIN;
import static org.apache.edgent.samples.connectors.mqtt.MqttClient.OPT_TOPIC;

import java.util.concurrent.TimeUnit;

import org.apache.edgent.connectors.mqtt.MqttConfig;
import org.apache.edgent.connectors.mqtt.MqttStreams;
import org.apache.edgent.samples.connectors.MsgSupplier;
import org.apache.edgent.samples.connectors.Options;
import org.apache.edgent.topology.TStream;
import org.apache.edgent.topology.Topology;
import org.apache.edgent.topology.TopologyProvider;

/**
 * A MQTT publisher topology application.
 */
public class PublisherApp {
    private final TopologyProvider tp;
    private final Options options;

    /**
     * @param tp the TopologyProvider to use.
     * @param options
     */
    PublisherApp(TopologyProvider tp, Options options) {
        this.tp = tp;
        this.options = options;
    }
    
    /**
     * Create a topology for the publisher application.
     * @return the Topology
     */
    public Topology buildAppTopology() {
        Topology t = tp.newTopology("mqttClientPublisher");
        
        // Create a sample stream of tuples to publish
        TStream<String> msgs = t.poll(new MsgSupplier(options.get(OPT_PUB_CNT)),
                                        1L, TimeUnit.SECONDS);

        // Create the MQTT broker connector
        MqttConfig config= Runner.newConfig(options);
        MqttStreams mqtt = new MqttStreams(t, () -> config);
        
        // Publish the stream to the topic.  The String tuple is the message value.
        mqtt.publish(msgs, options.get(OPT_TOPIC), 
                    options.get(OPT_QOS), options.get(OPT_RETAIN));
        
        return t;
    }

}