如何将数据添加到avro模式中的可重复字段? [英] how to add data to the repeatable fields in avro schema?

问题描述

我正在尝试在不生成代码的情况下测试avro serde和deserde(我使用代码生成完成了此任务).架构如下

I'm trying to test avro serde and deserde without code generation (I completed this task using code generation). Schema is as follows

{
"type": "record",
"name" : "person",
"namespace" : "avro",
"fields": [
    { "name" : "personname", "type": ["null","string"] },
    { "name" : "personId", "type": ["null","string"] },
    {  "name" : "Addresses", "type": {
        "type": "array",
        "items": [  {
          "type" : "record",
          "name" : "Address",
          "fields" : [
            { "name" : "addressLine1", "type": ["null", "string"] },
            { "name" : "addressLine2", "type": ["null", "string"] },
            { "name" : "city", "type": ["null", "string"] },
            { "name" : "state", "type": ["null", "string"] },
            { "name" : "zipcode", "type": ["null", "string"] }
            ]
        }]
        }
    },
    { "name" : "contact", "type" : ["null", "string"]}
]
}

我了解这是将数据添加到架构的方式.

I understand this is how data is added to the schema.

Schema schema = new Schema.Parser().parse(new File("src/person.avsc.txt"));
GenericRecord person1 = new GenericData.Record(schema);
person1.put("personname", "goud");

但是如何将城市，州等添加到地址，然后再将其添加到地址?

But how do I add city, state etc to address and then add it to addresses?

GenericRecord address1 = new GenericData.Record(schema);
address1.put("city", "SanJose");

以上代码段无效.我试图研究GenericArray，但无法解决.

The above snippet doesn't work. I tried to look into GenericArray, but I couldn't get my head around it.

推荐答案

您需要在单独的架构中描述内部复杂类型("type":"record"，"name":"Address")，如下所示:

You need to describe inner complex type ("type" : "record", "name" : "Address") in separate schema, like this:

{
  "type" : "record",
  "name" : "Address",
  "fields" : [
    { "name" : "addressLine1", "type": ["null", "string"] },
    { "name" : "addressLine2", "type": ["null", "string"] },
    { "name" : "city", "type": ["null", "string"] },
    { "name" : "state", "type": ["null", "string"] },
    { "name" : "zipcode", "type": ["null", "string"] }
  ]
}

然后您可以创建一个内部对象:

Then you may create an inner object:

Schema innerSchema = new Schema.Parser().parse(new File("person_address.avsc"));
GenericRecord address = new GenericData.Record(innerSchema);
address.put("addressLine1", "adr_1");
address.put("addressLine2", "adr_2");
address.put("city", "test_city");
address.put("state", "test_state");
address.put("zipcode", "zipcode_00000");

然后将您创建的内部对象添加到ArrayList.

Then add an inner object you created to ArrayList.

最后，创建主对象并将其添加到其中.

At last, create the main object and add all this staff in it.

以下是Java中的完整示例:

Here is full example in java:

Schema innerSchema = new Schema.Parser().parse(new File("person_address.avsc"));
GenericRecord address = new GenericData.Record(innerSchema);
address.put("addressLine1", "adr_1");
address.put("addressLine2", "adr_2");
address.put("city", "test_city");
address.put("state", "test_state");
address.put("zipcode", "zipcode_00000");

ArrayList<GenericRecord> addresses = new ArrayList<>();
addresses.add(address);

Schema mainSchema = new Schema.Parser().parse(new File("person.avsc"));
GenericRecord person1 = new GenericData.Record(mainSchema);
person1.put("personname", "goud");
person1.put("personId", "123_id");
person1.put("Addresses", addresses);

结果:

{
  "personname": "goud",
  "personId": "123_id",
  "Addresses": [
    {
      "addressLine1": "adr_1",
      "addressLine2": "adr_2",
      "city": "test_city",
      "state": "test_state",
      "zipcode": "zipcode_00000"
    }
  ],
  "contact": "test_contact"
}

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