使用apacheavro的javaavro阵列

Question

实际上，我的问题与下面链接中给出的答案类似（其中显示了使用avsc javascript库进行序列化/去序列化），但我需要一个解决方案来序列化到avro，并使用apache avro for java反序列化它

Avro schema for Json array

https://avro.apache.org/docs/current/gettingstartedjava.html

数据

[
 {"id":1,"text":"some text","user_id":1},
 {"id":1,"text":"some text","user_id":2},
 ...
]

模式

{
  "name": "Name",
  "type": "array",
  "namespace": "com.hi.avro.model",
  "items": {
    "name": "NameDetails",
    "type": "record",
    "fields": [
      {
        "name": "id",
        "type": "int"
      },
      {
        "name": "text",
        "type": "string"
      },
      {
        "name": "user_id",
        "type": "int"
      }
    ]
  }
}

谢谢你的帮助

Answer 1

我已经开始阅读API，并在我的代码中试用它

当我创建这个帖子时，我正努力把它分配给GenericRecord，但它不起作用。所以我发布了这个问题，因为我不清楚

最后，我没有将整个数组分配给GenericRecord，而是继续使用GenericArray并向其中添加GenericRecord

下面是代码片段

//到json

GenericArray record = new GenericDatumReader<GenericArray>(schema).read(null, binaryDecoder);

ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
NoWrappingJsonEncoder jsonEncoder = new NoWrappingJsonEncoder(record.getSchema(), outputStream);
DatumWriter<GenericArray> writer = record instanceof SpecificRecord ?
            new SpecificDatumWriter<>(record.getSchema()) :
            new GenericDatumWriter<>(record.getSchema());
    writer.write(record, jsonEncoder);
    jsonEncoder.flush();
byte[] result = outputStream.toByteArray();
    
    
    

//致阿夫罗

ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
BinaryEncoder encoder = EncoderFactory.get().binaryEncoder(outputStream, null);
GenericDatumWriter<Object> writer = new GenericDatumWriter(schema, genericData);
    
byte[] data;
    
List list = mapper.readValue(data, List.class);
    
GenericRecordBuilder record = new GenericRecordBuilder(schema.getElementType());
List<GenericData.Record> array = new ArrayList<>();

json.forEach(entry -> {
     //logic for reading GenericRecord for each of the list should be done here
     ...

     array.add(genericRecord);
});
    
writer.write(array, encoder);
     
encoder.flush();
     
byte[] result =  outputStream.toByteArray();