NodeStatusPublisher.java

Node Status Publication Example

This example shows how to write data from a real-time thread. Notice that it is not necessary to use the RTI DDS RTSJ configuration APIs in order to write data from a real-time thread that is under the direct control of the application.

The corresponding subscription code example can be found in the Node Status Subscription Example.

Source Code

/* NodeStatusPublisher.java

   A publication of data of type NodeStatus.

   This file is derived from code automatically generated by the rtiddsgen 
   command:

   rtiddsgen -language java -example <arch> NodeStatus.idl

   Example publication of type NodeStatus automatically generated by 
   'rtiddsgen' To test them follow these steps:

   (1) Compile this file and the example subscription.

   (2) Start the subscription on the same domain used for RTI Data Distribution
       Service with the command
       java NodeStatusSubscriber <domain_id> <sample_count>
       
   (3) Start the publication on the same domain used for RTI Data Distribution
       Service with the command
       java NodeStatusPublisher <domain_id> <sample_count>

   (4) [Optional] Specify the list of discovery initial peers and 
       multicast receive addresses via an environment variable or a file 
       (in the current working directory) called NDDS_DISCOVERY_PEERS.  
       
   You can run any number of publishers and subscribers programs, and can 
   add and remove them dynamically from the domain.
              
   Example:
        
       To run the example application on domain <domain_id>:
            
       Ensure that $(NDDSHOME)/lib/<arch> is on the dynamic library path for
       Java.                       
       
        On Unix: 
             add $(NDDSHOME)/lib/<arch> to the 'LD_LIBRARY_PATH' environment
             variable
                                         
        On Windows:
             add $(NDDSHOME)\lib<arch> to the 'Path' environment variable
                        

       Run the Java applications:
       
        java -Djava.ext.dirs=$NDDSHOME/class NodeStatusPublisher <domain_id>

        java -Djava.ext.dirs=$NDDSHOME/class NodeStatusSubscriber <domain_id>        
*/

package com.rti.ndds.rtsj.example.nodestatus;

import javax.realtime.ImmortalMemory;
import javax.realtime.MemoryArea;
import javax.realtime.MemoryParameters;
import javax.realtime.RealtimeThread;

import com.rti.dds.domain.DomainParticipant;
import com.rti.dds.domain.DomainParticipantFactory;
import com.rti.dds.infrastructure.InstanceHandle_t;
import com.rti.dds.infrastructure.StatusKind;
import com.rti.dds.publication.Publisher;
import com.rti.dds.topic.Topic;


// ===========================================================================

public class NodeStatusPublisher {
    // -----------------------------------------------------------------------
    // Public Methods
    // -----------------------------------------------------------------------
    
    public static void main(String[] args) {
        // --- Get domain ID --- //
        int domainId = 0;
        if (args.length >= 1) {
            domainId = Integer.valueOf(args[0]).intValue();
        }

        // -- Get max loop count; 0 means infinite loop --- //
        int sampleCount = 0;
        if (args.length >= 2) {
            sampleCount = Integer.valueOf(args[1]).intValue();
        }
        
        /* Uncomment this to turn on additional logging
        Logger.get_instance().set_verbosity_by_category(
                        LogCategory.NDDS_CONFIG_LOG_CATEGORY_API, 
                        LogVerbosity.NDDS_CONFIG_LOG_VERBOSITY_STATUS_ALL);
        */
        
        // --- Run --- //
        final int finalDomainId = domainId;
        final int finalSampleCount  = sampleCount;
        MemoryArea memArea = ImmortalMemory.instance();
        MemoryParameters memoryParameters = new MemoryParameters(
                1048576, 4 * 1048576);
        Thread thread = new RealtimeThread(
                null, null, memoryParameters, memArea, null,
                new Runnable() {
                    public void run() {
                        publisherMain(finalDomainId, finalSampleCount);
                    }
                }
            );
        thread.start();
    }
    
    
    
    // -----------------------------------------------------------------------
    // Private Methods
    // -----------------------------------------------------------------------
    
    // --- Constructors: -----------------------------------------------------
    
    private NodeStatusPublisher() {
        super();
    }
    
    
    // -----------------------------------------------------------------------
    
    private static void publisherMain(int domainId, int sampleCount) {
        DomainParticipant participant = null;
        try {
            // --- Create participant --- //
            /* To create participant with default QoS,
               use DomainParticipantFactory.DomainParticipantFactory.
                        participant.get_default_publisher_qos() instead */
            participant = DomainParticipantFactory.TheParticipantFactory.
                create_participant(
                    domainId, DomainParticipantFactory.PARTICIPANT_QOS_DEFAULT,
                    null /* listener */, StatusKind.STATUS_MASK_NONE);
        
            // --- Create publisher --- //
            /* To customize publisher QoS, use
               participant.get_default_publisher_qos() instead */
            Publisher publisher = participant.create_publisher(
                DomainParticipant.PUBLISHER_QOS_DEFAULT, null /* listener */,
                StatusKind.STATUS_MASK_NONE);
        
            // --- Create topic --- //
            /* Register type before creating topic */
            String typeName = NodeStatusTypeSupport.get_type_name();
            NodeStatusTypeSupport.register_type(participant, typeName);

            /* To customize topic QoS, use
               participant.get_default_topic_qos() instead */
            Topic topic = participant.create_topic(
                "Example NodeStatus",
                typeName, DomainParticipant.TOPIC_QOS_DEFAULT,
                null /* listener */, StatusKind.STATUS_MASK_NONE);
        
            // --- Create writer --- //
            /* To customize data writer QoS, use
               publisher.get_default_datawriter_qos() instead */
            NodeStatusDataWriter writer = (NodeStatusDataWriter)
                publisher.create_datawriter(
                    topic, Publisher.DATAWRITER_QOS_DEFAULT,
                    null /* listener */, StatusKind.STATUS_MASK_NONE);
        
            // --- Write --- //
            /* Create data sample for writing */
            NodeStatus instance = new NodeStatus();

            InstanceHandle_t instance_handle = InstanceHandle_t.HANDLE_NIL;
            /* For data type that has key, if the same instance is going to be
               written multiple times, initialize the key here
               and register the keyed instance prior to writing */
            //instance_handle = writer.register_instance(instance);

            final long sendPeriodMillis = 16; // 4 seconds

            for (int count = 0;
                 (sampleCount == 0) || (count < sampleCount);
                 ++count) {
                if (count%1024 == 0)
                    System.out.println("Writing NodeStatus, count " + count);

                /* Modify the instance to be written here */
            
                /* Write data */
                writer.write(instance, InstanceHandle_t.HANDLE_NIL);
                try {
                    Thread.sleep(sendPeriodMillis);
                } catch (InterruptedException ix) {
                    System.err.println("INTERRUPTED");
                    break;
                }
            }

            //writer.unregister_instance(instance, instance_handle);
        } finally {
            // --- Shutdown --- //
            if(participant != null) {
                participant.delete_contained_entities();

                DomainParticipantFactory.TheParticipantFactory.
                    delete_participant(participant);
            }
            /* RTI Data Distribution Service provides finalize_instance()
               method for people who want to release memory used by the
               participant factory singleton. Uncomment the following block of
               code for clean destruction of the participant factory
               singleton. */
            //DomainParticipantFactory.finalize_instance();
        }
    }
}