rustedbones / pekko-http-avro   1.0.0

Apache License 2.0 GitHub

pekko-http avro marshalling/unmarshalling for avro records

Scala versions: 3.x 2.13

pekko-http-avro

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pekko-http avro marshalling/unmarshalling for generated java avro specific records

Versions

Version Release date Pekko Http version Avro version Scala versions
1.0.0 2023-11-02 1.0.0 1.11.3 3.3.1, 2.13.12

The complete list can be found in the CHANGELOG file.

Getting pekko-http-avro

Libraries are published to Maven Central. Add to your build.sbt:

libraryDependencies += "fr.davit" %% "pekko-http-avro" % <version>

Quick start

For the examples, we are using the following avro domain model

{
  "namespace": "com.example",
  "type": "record",
  "name": "Item",
  "fields": [
    {
      "name": "name",
      "type": "string"
    },
    {
      "name": "id",
      "type": "long"
    }
  ]
}

and

{
  "namespace": "com.example",
  "type": "record",
  "name": "Order",
  "fields": [
    {
      "name": "items",
      "type": {
        "type" : "array",
        "items": "com.example.Item"
      }
    }
  ]
}

Marshalling/Unmarshalling of the generated classes depends on the Accept/Content-Type header sent by the client:

  • Content-Type: application/json: json
  • Content-Type: avro/raw: binary without schema
  • Content-Type: avro/binary: binary with schema (see schema resolution)

-No Accept header or matching several (eg Accept: application/*) will take the 1st matching type from the above list.

Avro

The implicit marshallers and unmarshallers for your generated avro classes are defined in AvroSupport. Specific (un)marshallers can be imported from AvroBinarySupport, AvroJsonSupport. You simply need to have them in scope.

import org.apache.pekko.http.scaladsl.server.Directives._
import fr.davit.pekko.http.scaladsl.marshallers.avro.AvroSupport._


object MyAvroService {

  val route =
    get {
      pathSingleSlash {
        complete(Item.newBuilder().setName("thing").setId(42).build())
      }
    } ~ post {
      entity(as[Order]) { order =>
        val itemsCount = order.getItems.size
        val itemNames = order.getItems.asScala.map(_.getName).mkString(", ")
        complete(s"Ordered $itemsCount items: $itemNames")
      }
    }
}

Limitation

Entity streaming (http chunked transfer) is at the moment not supported by the library.