org.apache.avro.AvroTypeException:未知的联合分支 [英] org.apache.avro.AvroTypeException: Unknown union branch

问题描述

我正在使用以下Avro模式:

I'm using this Avro schema:

prices-state.avsc

{
    "namespace": "com.company.model",
    "name": "Product",
    "type": "record",
    "fields": [
        {
            "name": "product_id",
            "type": "string"
        },
        {
            "name": "sale_prices",
            "type": {
                "name": "sale_prices",
                "type": "record",
                "fields": [
                    {
                        "name": "default",
                        "type": {
                            "name": "default",
                            "type": "record",
                            "fields": [
                                {
                                    "name": "order_by_item_price_by_item",
                                    "type": [
                                        "null",
                                        {
                                            "name": "markup_strategy",
                                            "type": "record",
                                            "fields": [
                                                {
                                                    "name": "type",
                                                    "type": {
                                                        "name": "type",
                                                        "type": "enum",
                                                        "symbols": ["margin", "sale_price"]
                                                    }
                                                }
                                            ]
                                        }
                                    ]
                                },
                                {"name": "order_by_item_price_by_weight", "type": ["null", "string"]},
                                {"name": "order_by_weight_price_by_weight", "type": ["null", "string"]}
                            ]
                        }
                    }
                ]
            }
        }
    ]
}

它可以在此网站上正确验证，所以我假设使用该模式有效.

It validates properly on this website so I'm assuming the schema is valid.

我在构建JSON文件时遇到问题，然后应使用上述架构对其进行编码.

I'm having issues building a JSON file that should then be encoded using the above schema.

我正在使用此JSON进行一些测试:

I'm using this JSON for some testing:

test.json

{
    "product_id": "123",
    "sale_prices": {
        "default": {
            "order_by_item_price_by_item": {
                "markup_strategy": {
                    "type": {"enum": "margin"}
                }
            },
            "order_by_item_price_by_weight": null,
            "order_by_weight_price_by_weight": null
        }
    }
}

运行java -jar avro-tools-1.8.2.jar fromjson --schema-file prices-state.avsc test.json时，我得到:

线程"main"中的异常org.apache.avro.AvroTypeException:未知的联合分支markup_strategy

Exception in thread "main" org.apache.avro.AvroTypeException: Unknown union branch markup_strategy

我在此处读到，我必须将东西包装在联合体内因为使用JSON编码，所以我尝试了不同的组合，但似乎没人能用.

I read here that I have to wrap things inside unions because of JSON Encoding so I tried different combinations but no one seemed to work.

推荐答案

这是一个命名空间解析问题.以这个简化的模式为例:

It was a namespace resolution issue. Take this simplified schema as an example:

test.avsc

{
    "name": "Product",
    "type": "record",
    "fields": [
        {
            "name": "order_by_item_price_by_item",
            "type": [
                "null",
                {
                    "type": "record",
                    "name": "markup_strategy",
                    "fields": [{
                        "name": "type",
                        "type": {
                            "name": "type",
                            "type": "enum",
                            "symbols": ["margin", "sale_price"]
                        }
                    }]
                }
            ]
        }
    ]
}

使用以下JSON可以很好地验证

With the following JSON it validates just fine

test.json

{
    "order_by_item_price_by_item": {
        "markup_strategy": {
            "type": "margin"
        }
    }
}

现在，如果要在架构顶部添加名称空间，例如

Now if you were to add a namespace on top of your schema like

test.avsc

{
    "namespace": "test",
    "name": "Product",
    "type": "record",
    "fields": [
    ...

然后，您还需要更改您的 test.json ，否则您将得到

Then you would need to change your test.json as well or you'll get

线程"main"中的异常org.apache.avro.AvroTypeException:未知的联合分支markup_strategy

Exception in thread "main" org.apache.avro.AvroTypeException: Unknown union branch markup_strategy

final_test.json

{
    "order_by_item_price_by_item": {
        "test.markup_strategy": {
            "type": "margin"
        }
    }
}

因此，当在联合类型中并且您使用用户指定的名称对JSON编码的Avro命名类型(记录，固定或枚举)时，该类型的名称也必须在名称空间名称之前添加分辨率.

So when inside a union type and you're JSON encoding an Avro's named type (record, fixed or enum) where the user-specified name is used then the name of that type needs to be prepended with the namespace name too for resolution.

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