IDLGenerator does not generate Java code for keyed topics.

[pavelpgt]

When I use IDLGenerator to generate Java code for keyed topics. The generated code still use unkeyed topics. What am I missing? It can be verified by adding publisherAttributes.getTopic().setTopicKind(TopicAttributes.TopicKind.WITH_KEY); subscriberAttributes.getTopic().setTopicKind(TopicAttributes.TopicKind.WITH_KEY); to PublisherExample and SubscriberExample (here). Then exception is thrown: java.lang.IllegalArgumentException: Keyed topic needs getKey function How can I properly use keyed topics? Thank you. Pavel

[jespersmith]

We have never tested keyed topics. I do not think the generator generates the correct code, and we have to add that functionality.

If it is for one or two classes, you can manually implement a getKey() function, but it's been a while since I looked at the format.

[pavelpgt]

Ok. Thanks for the reply. I will try to implement it.

[pavelpgt]

Hi. I am trying to manually implement a getKey() function but with no luck. What I did: I created idl: struct HelloWorld { @Key long id; string message; }; Generated HelloWorld.java and HelloWorldPubSubType.java by a generator.

I override getKey() function in HelloWroldPubSubType.java like this. public void getKey(cz.urc.dds.idl.HelloWorld data, ByteBuffer target) { if (this.isGetKeyDefined()) { data.serializeKey(serializeCDR); //Throws java.lang.NullPointerException } try { MessageDigest dig = MessageDigest.getInstance("MD5"); byte[] md5 = dig.digest(); for (int i=0; i < md5.length; ++i) { target.put(i, md5[i]); } } catch (NoSuchAlgorithmException e) { // TODO Auto-generated catch block e.printStackTrace(); } } I implemented serializeKey() function like this.

public void serializeKey(us.ihmc.idl.CDR scdr){ try { scdr.write_type_2(this.id_); } catch (Exception e) { System.out.println("serializeKey exception: " + e); } } But its throws Throws java.lang.NullPointerException, because serializeCDR is not initialized.

Could you please provide me with some help or insight on what should I do?

PS: When I do not implement the getKey method I get the [RTPS_WRITER Warning] Changes in KEYED Writers need a valid instanceHandle -> Function eprosima::fastrtps::rtps::RTPSWriter::new_change but the data are published and subscriber receives them.

Thank you. Pavel