vertx-avro-codec

A binary MessageCodec for the Vert.x event bus, backed by Apache Avro. Put your Avro SpecificRecord types directly on the event bus — no per-type serializer code, because the generated record carries its own schema.

Modules

Module	Purpose
order-schema	shared Avro schema (Order/OrderLineItem) and generated types, reused by the codec tests and the example
vertx-avro-codec	the reusable library — the generic codec
examples	a Kafka → event-bus verticle built with RxJava 3, proven by an integration test over a clustered event bus
benchmarks	JMH comparison of the Avro codec against Vert.x's default JsonObject codec and a Protobuf codec

Usage

// register once per message type
vertx.eventBus().registerDefaultCodec(Order.class, new AvroMessageCodec<>(Order.class));

// then send the generated Avro record straight onto the bus
vertx.eventBus().send("orders", new Order(1L, "espresso kit", List.of()));

Order here is your own Avro SpecificRecord, generated from a .avsc/.avdl schema in your project by the avro-maven-plugin. The library ships only the generic codec — bring any SpecificRecord type. (This repo keeps its Order/OrderLineItem fixtures in the separate order-schema module, so they never enter the library jar.)

When (not) to use this

This is a deliberately niche tool. It earns its keep when Avro is already your system's lingua franca — e.g. an Avro + Kafka + Schema-Registry shop building Vert.x services — letting the internal event bus reuse the same schemas and generated types as your Kafka topics instead of maintaining a second serialization dialect. If you are not already an Avro shop, prefer Vert.x's JSON codec or the Protobuf how-to.

History

This repository began in 2018 as an experiment in a custom binary event-bus codec (originally on Twitter Serial; tagged legacy-2018). It has since been modernized to Java 21 / Vert.x 5 and re-based on Apache Avro.

Build

mvn -B verify      # Java 21

Trademarks

vertx-avro-codec is an independent, unofficial project — not affiliated with, endorsed by, or sponsored by the Apache Software Foundation or the Eclipse Foundation. "Apache Avro" and "Avro" are trademarks of the Apache Software Foundation; "Eclipse Vert.x" and "Vert.x" are trademarks of the Eclipse Foundation. These names are used here only descriptively, to indicate compatibility and integration.