Avro是一種序列化數(shù)據(jù)的數(shù)據(jù)格式,它使用二進(jìn)制格式編碼數(shù)據(jù)。它的優(yōu)勢(shì)在于可以有效地壓縮數(shù)據(jù)并且提供了快速的反序列化能力。然而,當(dāng)我們需要使用JSON格式進(jìn)行數(shù)據(jù)交換時(shí),我們需要把數(shù)據(jù)從Avro格式轉(zhuǎn)換成JSON格式。
{ "namespace": "example.avro", "type": "record", "name": "User", "fields": [ {"name": "name", "type": "string"}, {"name": "email", "type": ["string", "null"]}, {"name": "age", "type": ["int", "null"]} ] }
以上是一個(gè)Avro數(shù)據(jù)格式的示例代碼。我們可以使用Avro提供的Java編程接口來(lái)讀取這個(gè)數(shù)據(jù)格式的數(shù)據(jù),并把它轉(zhuǎn)換成JSON格式。
import org.apache.avro.Schema; import org.apache.avro.generic.GenericDatumReader; import org.apache.avro.generic.GenericRecord; import org.apache.avro.io.DatumReader; import org.apache.avro.io.Decoder; import org.apache.avro.io.DecoderFactory; import org.json.JSONObject; public class AvroToJsonConverter { public static String convert(byte[] avroData) { Schema.Parser parser = new Schema.Parser(); Schema schema = parser.parse("{" + "\"namespace\": \"example.avro\"," + "\"type\": \"record\"," + "\"name\": \"User\"," + "\"fields\": [" + "{\"name\": \"name\", \"type\": \"string\"}," + "{\"name\": \"email\", \"type\": [\"string\", \"null\"]}," + "{\"name\": \"age\", \"type\": [\"int\", \"null\"]}" + "]" + "}"); DatumReaderdatumReader = new GenericDatumReader<>(schema); Decoder decoder = DecoderFactory.get().binaryDecoder(avroData, null); GenericRecord record = datumReader.read(null, decoder); JSONObject json = new JSONObject(record.toString()); return json.toString(); } }
以上是一個(gè)Java代碼示例,可以將Avro轉(zhuǎn)換成JSON。該代碼首先定義了Avro數(shù)據(jù)格式的schema,然后使用Avro的Java編程接口讀取Avro數(shù)據(jù),然后使用JSON API將其轉(zhuǎn)換成JSON格式并返回。