Sending Java objects over event bus

[Eranga Samararathna]

Hi,

Few questions in my mind.

1.) Is it possible to send Java objects over vert.x event bus?
2.) What is the serialization mechanism used in vert.x ? Java standard serialization ??

If vert.x use Java standard serialization;   Any idea about the effort need to convert that to something else like Kryo

Thanks

Era.

[Nick Scavelli]

Answers inline

On Monday, June 30, 2014 8:10:55 AM UTC-4, Eranga Samararathna wrote:

Hi,

Few questions in my mind.

1.) Is it possible to send Java objects over vert.x event bus?

Not at the moment. Something we're working on for 3.0

 

2.) What is the serialization mechanism used in vert.x ? Java standard serialization ??

No, it's manual. Since we know what types are being sent (String, Integer, Double, JsonObject) we just convert them down to bytes.

[Jamie B]

Perhaps simply exposing support for Hazelcast's Portable serialisation? This would allow serialisation via any means desired by the developer (as well as out-the-box options).

[qsys]

Well, actually: yes. Serialize to byte array and you're set. I'm using FST serialization in most cases, json or json array serialization in other cases.
This is how it more or less looks like for FST serialization (exceptions not properly handled):

   private final FSTConfiguration fstConf = FSTConfiguration.createDefaultConfiguration();
 
   @Override
   public void handle(final Message<String> message) {
      [...]
      final ByteArrayOutputStream arrayOut = new ByteArrayOutputStream();
      final FSTObjectOutput out = this.fstConf.getObjectOutput(arrayOut);
      try {
         out.writeObject(someObject, SomeObject.class);
         out.flush();
      } catch (final IOException e) {
         e.printStackTrace();
      }
      message.reply(out.getBuffer());
      try {
         arrayOut.close();
      } catch (final IOException e) {
         e.printStackTrace();
      }
   }

and:

       [...]
        new Handler<Message<byte[]>>() {
            @Override
            public void handle(final Message<byte[]> event) {
               final ByteArrayInputStream byteArray = new ByteArrayInputStream(event.body());
               try {
                  final FSTObjectInput in = SomeHandler.this.fstConf.getObjectInput(byteArray);
                  final T result = ((T) in.readObject());
                  byteArray.close();
               } catch (final IOException | ClassNotFoundException | InterruptedException e) {
                  e.printStackTrace();
               }
            }
         });
     [...]

Op maandag 30 juni 2014 14:10:55 UTC+2 schreef Eranga Samararathna:

[Eranga Samararathna]

Thanks qsys. How do you send FST serialized object over event bus ? as a vert.x buffer ??

[qsys]

So far, only as a byte[], for example, this line converts the serialized object to a byte array and sends the byte array back to the 'requestor':

message.reply(out.getBuffer())

On the client side, I receive a byte[]:

new Handler<Message<byte[]>>() {...}

All I do in the 'handle'-method, is reading the object to 'result'. It's embedded inside some other stuff, hence the generic T. But I suppose you get the idea... You can use kryo (or any other serialization) if you want. All you need is a byte array...

greetz, qsys



Op dinsdag 1 juli 2014 12:05:01 UTC+2 schreef Eranga Samararathna:

[Eranga Samararathna]

Thanks qsys. I'll give a try.

On Monday, June 30, 2014 5:40:55 PM UTC+5:30, Eranga Samararathna wrote: