Apache Avro：复杂的 POJO 对象作为 Map 的值

Question

Consider some POJOs such as follows.

class Configuration {
  private String id;
  private Map<String, LocationConfig> locationConfiguration;
}

class LocationConfig {
  private String locationId;
  private Integer capacity;
  private Boolean available;
}

How can I come up with a JSON based Avro schema for the above? As far as I could find, even though maps are supported in Avro, the key type should always be String (which I can somehow live with) and the values cannot be of Record type. Is there a way around this? The documentation has only follows.

Upon research I could find somewhat of a similar question , which doesn't look very useful.

Answer 1

Yes you can add complex POJO as Map's value.

For eg I had below schema initially

{
            "type": "record",
            "name": "click_event",
            "namespace": "exercise2",
            "fields": [
                {"name": "email", "type": "string"},
                {"name": "timestamp", "type": "string"},
                {"name": "uri", "type": "string"},
                {"name": "number", "type": "int"},
            ],
}

Then I wanted to add a complex type ie map which in turn contained POJO objects.

{
'about': 
  ClickAttribute(element='a', content='reinvent intuitive infrastructures'), 
'index': 
  ClickAttribute(element='button', content='repurpose cross-media schemas')
}

I added it in this way

{
            "type": "record",
            "name": "click_event",
            "namespace": "exercise2",
            "fields": [
                {"name": "email", "type": "string"},
                {"name": "timestamp", "type": "string"},
                {"name": "uri", "type": "string"},
                {"name": "number", "type": "int"},
                # Below complex type is added by me.
                {
                    "name" : "attributes",
                    "type" : {
                        "type" : "map",
                        "values" : {
                            "name" : "click_attribute",
                            "type" : "record",
                            "fields" : [
                                {"name" : "element", "type" : "string"},
                                {"name" : "content", "type" : "string"}
                            ]
                        }
                    }
                }
            ],
}