flink kafka consumer with avro schema. handling null

Posted 2020-11-27 connie313

public class AvroDeserializationSchema<T> implements DeserializationSchema<T> {

    private static final long serialVersionUID = 1L;

    private final Class<T> avroType;

    private transient DatumReader<T> reader;
    private transient BinaryDecoder decoder;

    public AvroDeserializationSchema(Class<T> avroType) {
        this.avroType = avroType;
    }


    public T deserialize(byte[] message) {
        ensureInitialized();
        try {
            decoder = DecoderFactory.get().binaryDecoder(message, decoder);
            T t = reader.read(null, decoder);
            return t;
        } catch (Exception ex) {
            throw new RuntimeException(ex);
        }
    }

    private void ensureInitialized() {
        if (reader == null) {
            if (org.apache.avro.specific.SpecificRecordBase.class.isAssignableFrom(avroType)) {
                reader = new SpecificDatumReader<T>(avroType);

 } else {
                reader = new ReflectDatumReader<T>(avroType);
            }
        }
    }


    public boolean isEndOfStream(T nextElement) {
        return false;
    }


    public TypeInformation<T> getProducedType() {
        return TypeExtractor.getForClass(avroType);
    }
}

https://developer.aliyun.com/ask/131116?spm=a2c6h.13159736


https://ci.apache.org/projects/flink/flink-docs-release-1.10/dev/connectors/kafka.html