Create a Demo Application using the Directory Service.

The project directory-binding-dnssd provides a DNSSD directory binding implementation.
Instead of using the DNSSD binding, we will implement a DummyDirectoryBinding in this example.
The ch.fhnw.bacnetit.ase.network.directory.api.DirectoryService class is the directory interface used by applications and bacnet devices.
All directory bindings implement the ch.fhnw.bacnetit.ase.network.directory.api.DirectoryBinding interface.

Create a java class called DummyDirectoryBinding.java that implements DirectoryBinding.

import java.net.URI;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.concurrent.ConcurrentHashMap;
import ch.fhnw.bacnetit.ase.encoding.api.BACnetEID;
import ch.fhnw.bacnetit.ase.network.directory.api.DirectoryBinding;

// All directory bindings have to implement the DirectoryBinding interface
public class DummyDirectoryBinding implements DirectoryBinding {
    
    // BACnetEID of bds
    private volatile BACnetEID bds = null;
    // Records
    private volatile Map<BACnetEID, URI> records = new ConcurrentHashMap<BACnetEID,URI>();
    
    public DummyDirectoryBinding(){
        
        // Thread to print the current state of records.
        new Thread(new Runnable(){
            @Override
            public void run() {
                
                while(true){
                    StringBuffer sb = new StringBuffer();
                    for (Entry<BACnetEID, URI> entry : records.entrySet()) {
                        sb.append(entry.getKey().getIdentifierAsString()+"->"+entry.getValue()+"\n****\n");
                    }
                    System.out.println("DirectoryBinding:\nBDS:" + ((bds!=null) ? bds.getIdentifierAsString():"not set")+"\n"+sb.toString());
                    try {
                        Thread.sleep(3000);
                    } catch (InterruptedException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                }
            }
        }).start();
    }

    @Override
    public void delete(BACnetEID arg0) {
        // TODO Auto-generated method stub
        
    }

    @Override
    public List<BACnetEID> findBDS() {
        if (this.bds != null ){
            List<BACnetEID> bdss = new LinkedList<BACnetEID>();
            bdss.add(bds);
            return bdss;
        }
        return null;
    }

    @Override
    public void register(BACnetEID bacnetEID, URI uri, boolean isBds) {
        if (bacnetEID == null)
                return;
        if (isBds && this.bds == null){
            this.bds = bacnetEID;
            System.out.println("BDS set");
        }
        // Overwrite existing values
        records.put(bacnetEID, uri);
       
        
    }

    @Override
    public void registerObject(String arg0, boolean arg1, String arg2,
            BACnetEID arg3, String arg4, int arg5, int arg6) {
        // TODO Auto-generated method stub
        
    }

    @Override
    public URI resolve(BACnetEID bacnetEID) {
        return this.records.get(bacnetEID);
    }
}

Extend the method onIndication(T_UnitDataIndication tUnitDataIndication, Object context) of bacnet device 1001 in class Application1.java with a further else if case.
That case will handle incoming AddListElementRequests. (Contains information about the bacnet device that should be registered)

                // Device 1001 of application 1 is BDS. Therefore it has to handle remote directory register requests
                else if (incoming instanceof ConfirmedRequest && ((ConfirmedRequest)incoming).getServiceRequest() instanceof AddListElementRequest){
                    SequenceOf<?> charcterStrings = ((AddListElementRequest)((ConfirmedRequest)incoming).getServiceRequest()).getListOfElements();
                    System.out.println("BDS got an AddListElementRequest");
                    for (Encodable cs : charcterStrings ) {
                        try {
                            DirectoryService.getInstance().register(arg0.getData().getSourceEID(), new URI(cs.toString()), false, false);
                        } catch (URISyntaxException e) {
                            // TODO Auto-generated catch block
                            e.printStackTrace();
                        }
                    }
                }

Adjust class Configurator

Let device 1001 be the BDS. The BDS registers itself directly using DirectoryService. All other devices send AddListElementRequest towards the BDS to register themselves.

  DirectoryService.init();
 DirectoryService.getInstance().setDNSBinding(new DummyDirectoryBinding());

  // Register device 1001 as BDS
 DirectoryService.getInstance().register(
 		application1.devices.get(0).getEID(),
      new URI("ws://localhost:8080"), true, false);

Let devices 1002, 2001 and 2002 register themselves by sending AddListElementRequests to the BDS.

   		// Register 1002 using BDS
          ByteQueue bq = new ByteQueue(
                  performRegisterOverBds(
                  	application1.devices.get(1).getEID(),
                   	new URI("ws://localhost:8080"),
                    	application1.devices.get(0).getEID()));

          application1.sendBACnetMessage(
                  DirectoryService.getInstance()
                          .resolve(DirectoryService.getInstance().getBds()),
                  application1.devices.get(1).getEID(),
                  application1.devices.get(0).getEID(), bq.popAll());

          // Register 2001 using BDS
          bq = new ByteQueue(
                  performRegisterOverBds(application2.devices.get(0).getEID(),
                          new URI("ws://localhost:9090"),
                          application1.devices.get(0).getEID()));

          application2.sendBACnetMessage(
                  DirectoryService.getInstance()
                          .resolve(DirectoryService.getInstance().getBds()),
                  application2.devices.get(0).getEID(),
                  application1.devices.get(0).getEID(), bq.popAll());

          // Register 2002 using BDS
          bq = new ByteQueue(
                  performRegisterOverBds(application2.devices.get(1).getEID(),
                    	new URI("ws://localhost:9090"),
                     application1.devices.get(0).getEID()));

          application2.sendBACnetMessage(
                  DirectoryService.getInstance()
                          .resolve(DirectoryService.getInstance().getBds()),
                  application2.devices.get(1).getEID(),
                  application1.devices.get(0).getEID(), bq.popAll());
   
 // Additional method to build a AddListElementRequest. Consider the BACnet/IT spec for the detailed and correct structure.
 public static byte[] performRegisterOverBds(BACnetEID who, URI location,BACnetEID bds) {
      final SequenceOf<CharacterString> uriChars = new SequenceOf<CharacterString>();
      uriChars.add(new CharacterString(location.toString()));
      final AddListElementRequest request = new AddListElementRequest(
              new BACnetObjectIdentifier(BACnetObjectType.multiStateInput, 1),
              BACnetPropertyIdentifier.stateText, null, uriChars);
      final ByteQueue byteQueue = new ByteQueue();
      request.write(byteQueue);
      return byteQueue.popAll();
  }

Replace the fix destination URIs by a DirectoryService.getInstance().resolve() invoke.

  application1.sendReadPropertyRequestUsingBACnet4j(
          DirectoryService.getInstance().resolve(new BACnetEID(2001)),
          new BACnetEID(1001), new BACnetEID(2001));
	
  //...
	
  application2.sendBACnetMessage(
          DirectoryService.getInstance().resolve(new BACnetEID(1001)),
          new BACnetEID(2001), new BACnetEID(1001), whoIsRequest);

Note the detailed sequence diagram about the tasks of the Configurator in a setup with Directory Service: Picture

Note the detailed system overview: Picture

Go to Build from source

fhnw-bacnet-it.github.io

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Create a Demo Application using the Directory Service.