io.atleon.avro.AtleonReflectData Maven / Gradle / Ivy
package io.atleon.avro;
import org.apache.avro.Schema;
import org.apache.avro.reflect.ReflectData;
import org.apache.avro.reflect.ReflectDatumReader;
import org.apache.avro.specific.SpecificData;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
import java.util.SortedSet;
import java.util.TreeSet;
import java.util.function.Supplier;
public final class AtleonReflectData extends ReflectData {
private static final AtleonReflectData INSTANCE = new AtleonReflectData();
public static AtleonReflectData get() {
return INSTANCE;
}
@Override
public ReflectDatumReader createDatumReader(Schema writer, Schema reader) {
return new AtleonReflectData.DatumReader<>(writer, reader, this);
}
public static final class AllowNull extends ReflectData.AllowNull {
@Override
public ReflectDatumReader createDatumReader(Schema writer, Schema reader) {
return new AtleonReflectData.DatumReader<>(writer, reader, this);
}
}
/**
* At one point, Avro did not know how to handle the deserialization of certain abstract types,
* like Sets and SortedSets. This DatumReader addresses types we wanted to support at ToW.
* Clients that need to support other types should be able to follow a similar pattern
*/
private static final class DatumReader extends ReflectDatumReader {
private static final Map> CREATORS_BY_CLASS_NAME = createCreatorsByClassName();
public DatumReader(Schema writer, Schema reader, ReflectData data) {
super(writer, reader, data);
}
@Override
protected Object newArray(Object old, int size, Schema schema) {
Supplier creator = CREATORS_BY_CLASS_NAME.get(schema.getProp(SpecificData.CLASS_PROP));
return old == null && creator != null ? creator.get() : super.newArray(old, size, schema);
}
private static Map> createCreatorsByClassName() {
Map> creatorsByClassName = new HashMap<>();
creatorsByClassName.put(Set.class.getName(), HashSet::new);
creatorsByClassName.put(SortedSet.class.getName(), TreeSet::new);
return creatorsByClassName;
}
}
}