avro/src/test/resources/user.avsc

{
    "namespace": "org.apache.mina.avro.generated",
    "type": "record",
    "name": "User",
    "fields": [
                {"name": "name", "type": "string"},
                {"name": "favorite_number",  "type": ["int", "null"]},
                {"name": "favorite_color", "type": ["string", "null"]}
              ]
}