| package samza.examples.avro; |
| |
| import java.io.ByteArrayOutputStream; |
| import java.io.IOException; |
| import org.apache.avro.Schema; |
| import org.apache.avro.generic.GenericDatumReader; |
| import org.apache.avro.generic.GenericDatumWriter; |
| import org.apache.avro.generic.GenericRecord; |
| import org.apache.avro.generic.IndexedRecord; |
| import org.apache.avro.io.BinaryDecoder; |
| import org.apache.avro.io.DatumWriter; |
| import org.apache.avro.io.DecoderFactory; |
| import org.apache.avro.io.Encoder; |
| import org.apache.avro.io.EncoderFactory; |
| import org.apache.samza.SamzaException; |
| import org.apache.samza.config.Config; |
| import org.apache.samza.serializers.Serde; |
| import org.apache.samza.serializers.SerdeFactory; |
| |
| |
| public class AvroSerDeFactory implements SerdeFactory { |
| |
| public static String CFG_AVRO_SCHEMA = "serializers.avro.schema"; |
| |
| @Override |
| public Serde getSerde(String name, Config config) { |
| return new AvroSerDe(config); |
| } |
| |
| private class AvroSerDe implements Serde { |
| private final Schema schema; |
| |
| public AvroSerDe(Config config) { |
| schema = Schema.parse(config.get(CFG_AVRO_SCHEMA)); |
| } |
| |
| @Override |
| public Object fromBytes(byte[] bytes) { |
| GenericRecord record; |
| try { |
| record = genericRecordFromBytes(bytes, schema); |
| } catch (IOException e) { |
| throw new SamzaException("Unable to deserialize the record", e); |
| } |
| return record; |
| } |
| |
| @Override |
| public byte[] toBytes(Object o) { |
| GenericRecord record = (GenericRecord) o; |
| try { |
| return encodeAvroGenericRecord(schema, record); |
| } catch (IOException e) { |
| throw new SamzaException("Unable to serialize the record", e); |
| } |
| } |
| } |
| |
| public byte[] encodeAvroGenericRecord(Schema schema, GenericRecord record) throws IOException { |
| DatumWriter<IndexedRecord> msgDatumWriter = new GenericDatumWriter<>(schema); |
| ByteArrayOutputStream os = new ByteArrayOutputStream(); |
| Encoder encoder = EncoderFactory.get().binaryEncoder(os, null); |
| msgDatumWriter.write(record, encoder); |
| encoder.flush(); |
| return os.toByteArray(); |
| } |
| |
| private static <T> T genericRecordFromBytes(byte[] bytes, Schema schema) throws IOException { |
| BinaryDecoder binDecoder = DecoderFactory.defaultFactory().createBinaryDecoder(bytes, null); |
| GenericDatumReader<T> reader = new GenericDatumReader<>(schema); |
| return reader.read(null, binDecoder); |
| } |
| } |