Extend from RemoteDevice

[Andreas Vogt]

Hi guys,
If I "extend" from the class "RemoteDevice" and then create a object of that, I can't use it to send regular BACnet requests. I always run in a NullPointerException.

/17:02:40.933 [BACnet4J transport for device 10001] ERROR com.serotonin.bacnet4j.transport.DefaultTransport - Error during send: OutgoingConfirmed [maxAPDULengthAccepted=-1, segmentationSupported=null, service=ReadPropertyRequest [objectIdentifier=device 2098177, propertyIdentifier=object-list, propertyArrayIndex=null], consumer=com.serotonin.bacnet4j.transport.ServiceFutureImpl@10a4064, address=Address [networkNumber=0, macAddress=[c0,a8,1,b1,ba,c0]], linkService=null]
java.lang.NullPointerException: null
	at com.serotonin.bacnet4j.transport.DefaultTransport$OutgoingConfirmed.sendImpl(DefaultTransport.java:380)
	at com.serotonin.bacnet4j.transport.DefaultTransport$Outgoing.send(DefaultTransport.java:336)
	at com.serotonin.bacnet4j.transport.DefaultTransport.run(DefaultTransport.java:486)
	at java.base/java.lang.Thread.run(Thread.java:830)
17:02:40.933 [BACnet4J transport for device 10001] ERROR com.serotonin.bacnet4j.transport.DefaultTransport - Original send stack
java.lang.Exception: null
	at com.serotonin.bacnet4j.transport.DefaultTransport.send(DefaultTransport.java:292)
	at com.serotonin.bacnet4j.transport.DefaultTransport.send(DefaultTransport.java:283)
	at com.serotonin.bacnet4j.LocalDevice.send(LocalDevice.java:989)
	at com.serotonin.bacnet4j.util.RequestUtils.sendOneAtATime(RequestUtils.java:425)
	at com.serotonin.bacnet4j.util.RequestUtils.readProperties(RequestUtils.java:396)
	at com.serotonin.bacnet4j.util.RequestUtils.readProperties(RequestUtils.java:257)
	at com.serotonin.bacnet4j.util.RequestUtils.getProperties(RequestUtils.java:141)
	at com.serotonin.bacnet4j.util.RequestUtils.getProperties(RequestUtils.java:136)
	at com.bacnetbrowser.schoko.DeviceTest$Listener.iAmReceived(DeviceTest.java:40)
	at com.serotonin.bacnet4j.event.DeviceEventHandler.fireIAmReceived(DeviceEventHandler.java:97)
	at com.serotonin.bacnet4j.service.unconfirmed.IAmRequest.lambda$handle$0(IAmRequest.java:118)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
	at java.base/java.lang.Thread.run(Thread.java:830)

The code I used for testing:

public class DeviceTest {
    static LocalDevice localDevice;

    public static void main(String[] args) throws Exception {
        int localDevice_ID = 10001;
        IpNetworkBuilder ipNetworkBuilder = new IpNetworkBuilder();
        ipNetworkBuilder.withLocalBindAddress(IpNetwork.DEFAULT_BIND_IP);
        ipNetworkBuilder.withBroadcast("255.255.255.255", IpNetwork.BVLC_TYPE);
        ipNetworkBuilder.withPort(47808);
        DefaultTransport transport = new DefaultTransport(ipNetworkBuilder.build());
        localDevice = new LocalDevice(localDevice_ID, transport);
        localDevice.getEventHandler().addListener(new Listener());
        localDevice.initialize();
        localDevice.startRemoteDeviceDiscovery();
    }

    static class Listener extends DeviceEventAdapter {
        @Override
        public void iAmReceived(RemoteDevice d) {
            System.out.println("I am received" + d);
            Device device = new Device(localDevice, d.getInstanceNumber(), d.getAddress());
            try {
                Map<PropertyIdentifier, Encodable> values = RequestUtils.getProperties(
                        localDevice, device, device.getObjectIdentifier(),null,
                        PropertyIdentifier.objectList);
                System.out.println(values);
            } catch (BACnetException e) {
                e.printStackTrace();
            }
        }
    }

    static class Device extends RemoteDevice{
        public Device(LocalDevice localDevice, int instanceNumber, Address address) {
            super(localDevice, instanceNumber, address);
        }
    }

}

I would be glad if somone could have a look and give me a feedback ;-)

BR
Andreas

[terrypacker]

@andreas-vogt what version of the code are you using? I can't see how that happens when reading the code on the master branch of BACnet4J. I would suggest you put a breakpoint in and find what is null. Then let me know and I can help you from there.

[Andreas Vogt]

Hello @terrypacker, thank you for answering! :)

I am using:

<dependency>
	<groupId>com.infiniteautomation</groupId>
	<artifactId>bacnet4j</artifactId>
	<version>5.0.2</version>
</dependency>

As I followd the stacktrace I found in the "DefaultTransport" that at the line 769 "Segmentation" is needed. So the "Segmentation" is the object which is null in the "extended" class.
If I try:

static class Listener extends DeviceEventAdapter {
  @Override
  public void iAmReceived(RemoteDevice d) {

  //Not null
  d.getSegmentationSupported();
  Device device = new Device(localDevice,d.getInstanceNumber(),d.getAddress());

  //Here happens a null pointer
  device.getSegmentationSupported();
  }
}

Therefore I was thinking of override this property and tried this:

public class DeviceTest {
    static LocalDevice localDevice;

    public static void main(String[] args) throws Exception {
        int localDevice_ID = 10001;
        IpNetworkBuilder ipNetworkBuilder = new IpNetworkBuilder();
        ipNetworkBuilder.withLocalBindAddress(IpNetwork.DEFAULT_BIND_IP);
        ipNetworkBuilder.withBroadcast("255.255.255.255", IpNetwork.BVLC_TYPE);
        ipNetworkBuilder.withPort(47808);
        DefaultTransport transport = new DefaultTransport(ipNetworkBuilder.build());
        localDevice = new LocalDevice(localDevice_ID, transport);
        localDevice.getEventHandler().addListener(new Listener());
        localDevice.initialize();
        localDevice.startRemoteDeviceDiscovery();
    }

    static class Listener extends DeviceEventAdapter {
        @Override
        public void iAmReceived(RemoteDevice d) {
            Device device = new Device(localDevice, d.getInstanceNumber(), d.getAddress(), d.getSegmentationSupported());
            try {
                Map<PropertyIdentifier, Encodable> values = RequestUtils.getProperties(
                        localDevice, device, device.getObjectIdentifier(),null,
                        PropertyIdentifier.objectList);
                System.out.println(values);
            } catch (BACnetException e) {
                e.printStackTrace();
            }
        }
    }

    static class Device extends RemoteDevice{
        Segmentation segmentation;

        public Device(LocalDevice localDevice, int instanceNumber, Address address, Segmentation segmentation) {
            super(localDevice, instanceNumber, address);
            this.segmentation = segmentation;
        }

        @Override
        public Segmentation getSegmentationSupported() {
            return this.segmentation;
        }
    }
}

But I am running in a new exception:

10:32:31.350 [BACnet4J transport for device 10001] ERROR com.serotonin.bacnet4j.transport.DefaultTransport - Error during send: OutgoingConfirmed [maxAPDULengthAccepted=-1, segmentationSupported=segmented-both, service=ReadPropertyRequest [objectIdentifier=device 2098177, propertyIdentifier=object-list, propertyArrayIndex=null], consumer=com.serotonin.bacnet4j.transport.ServiceFutureImpl@36f5e9d5, address=Address [networkNumber=0, macAddress=[c0,a8,1,b1,ba,c0]], linkService=null]
java.lang.NegativeArraySizeException: -7
	at com.serotonin.bacnet4j.transport.DefaultTransport$OutgoingConfirmed.sendImpl(DefaultTransport.java:392)
	at com.serotonin.bacnet4j.transport.DefaultTransport$Outgoing.send(DefaultTransport.java:336)
	at com.serotonin.bacnet4j.transport.DefaultTransport.run(DefaultTransport.java:486)
	at java.base/java.lang.Thread.run(Thread.java:830)
10:32:31.350 [BACnet4J transport for device 10001] ERROR com.serotonin.bacnet4j.transport.DefaultTransport - Original send stack
java.lang.Exception: null
	at com.serotonin.bacnet4j.transport.DefaultTransport.send(DefaultTransport.java:292)
	at com.serotonin.bacnet4j.transport.DefaultTransport.send(DefaultTransport.java:283)
	at com.serotonin.bacnet4j.LocalDevice.send(LocalDevice.java:989)
	at com.serotonin.bacnet4j.util.RequestUtils.sendOneAtATime(RequestUtils.java:425)
	at com.serotonin.bacnet4j.util.RequestUtils.readProperties(RequestUtils.java:396)
	at com.serotonin.bacnet4j.util.RequestUtils.readProperties(RequestUtils.java:257)
	at com.serotonin.bacnet4j.util.RequestUtils.getProperties(RequestUtils.java:141)
	at com.serotonin.bacnet4j.util.RequestUtils.getProperties(RequestUtils.java:136)
	at com.bacnetbrowser.schoko.DeviceTest$Listener.iAmReceived(DeviceTest.java:41)
	at com.serotonin.bacnet4j.event.DeviceEventHandler.fireIAmReceived(DeviceEventHandler.java:97)
	at com.serotonin.bacnet4j.service.unconfirmed.IAmRequest.lambda$handle$0(IAmRequest.java:118)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
	at java.base/java.lang.Thread.run(Thread.java:830)

This time there sems a problem with the getMaxAPDULengthAccepted() of the Remote Device so I overrided this property as well:

public class DeviceTest {
    static LocalDevice localDevice;

    public static void main(String[] args) throws Exception {
        int localDevice_ID = 10001;
        IpNetworkBuilder ipNetworkBuilder = new IpNetworkBuilder();
        ipNetworkBuilder.withLocalBindAddress(IpNetwork.DEFAULT_BIND_IP);
        ipNetworkBuilder.withBroadcast("255.255.255.255", IpNetwork.BVLC_TYPE);
        ipNetworkBuilder.withPort(47808);
        DefaultTransport transport = new DefaultTransport(ipNetworkBuilder.build());
        localDevice = new LocalDevice(localDevice_ID, transport);
        localDevice.getEventHandler().addListener(new Listener());
        localDevice.initialize();
        localDevice.startRemoteDeviceDiscovery();
    }

    static class Listener extends DeviceEventAdapter {
        @Override
        public void iAmReceived(RemoteDevice d) {
            Device device = new Device(localDevice, d.getInstanceNumber(), d.getAddress(), d.getSegmentationSupported());
            try {
                Map<PropertyIdentifier, Encodable> values = RequestUtils.getProperties(
                        localDevice, device, device.getObjectIdentifier(),null,
                        PropertyIdentifier.objectList);
                System.out.println(values);
            } catch (BACnetException e) {
                e.printStackTrace();
            }
        }
    }

    static class Device extends RemoteDevice{
        Segmentation segmentation;
        int maxAPDULengthAccepted = 1476;

        public Device(LocalDevice localDevice, int instanceNumber, Address address, Segmentation segmentation) {
            super(localDevice, instanceNumber, address);
            this.segmentation = segmentation;
        }

        @Override
        public Segmentation getSegmentationSupported() {
            return this.segmentation;
        }

        @Override
        public int getMaxAPDULengthAccepted() {
            return maxAPDULengthAccepted;
        }
    }
}

This is working but I do not know if I am on the right way.

BR
Andreas

[terrypacker]

@Andreas-Vogt you are not on the correct path with this solution. I suggest you take a look at how the IamRequest class calls iAmReceived(RemoteDevice d).

Specifically this section of code from around line 110:

final RemoteDevice rd = new RemoteDevice(localDevice, remoteDoi, from);
rd.setDeviceProperty(PropertyIdentifier.maxApduLengthAccepted, maxAPDULengthAccepted);
rd.setDeviceProperty(PropertyIdentifier.segmentationSupported, segmentationSupported);
rd.setDeviceProperty(PropertyIdentifier.vendorIdentifier, vendorId);

[Andreas Vogt]

Hi guys, its been a while since I opened this thread. I am sorry for my late answer but I was very busy lately..
I have followed the call @terrypacker has mentioned and wanted to let you konw how I implemnted my BACnetDevice class which extends from the RemoteDevice back then. I am sure there is a better way but for me it is working. I guess that there are not many cases in which someone really needs to "extend" from Remotedevice.
But...
I'll have a closer look in the next weeks cause I'll do a littlebit refactoring in my code, if I can get a better solution I'll post the progress here. Just in case someone needs to know :)

So my current implementation:

In the constructor of my own class I am forcing to implement the missing properties.

public BACnetDevice(LocalDevice localDevice, int instanceNumber, Address address, Segmentation segmentation,
                  int vendorIdentifier,int maxAPDULengthAccepted) {
        super(localDevice, instanceNumber, address);
        this.setDeviceProperty(PropertyIdentifier.maxApduLengthAccepted, new UnsignedInteger(maxAPDULengthAccepted));
        this.setDeviceProperty(PropertyIdentifier.segmentationSupported, segmentation);
        this.setDeviceProperty(PropertyIdentifier.vendorIdentifier, new UnsignedInteger(vendorIdentifier));
    }

By the listener I am fetching the needed properties from the existing instanz

@Override
    public void iAmReceived(RemoteDevice d) {
        BACnetDevice bacnetDevice = new BACnetDevice(localDevice, d.getInstanceNumber(), d.getAddress(),
                d.getSegmentationSupported(), d.getVendorIdentifier(), d.getMaxAPDULengthAccepted());
        waitingRoomBacnetDevices.put(bacnetDevice.getInstanceNumber(), bacnetDevice);
        LOG.info("Remote device " + d.getInstanceNumber() + " registered in waiting room of LocalDevice");
    }