package com.netflix.astyanax.entitystore;
import java.lang.reflect.Field;
import java.nio.ByteBuffer;
import javax.persistence.Column;
import javax.persistence.OrderBy;
import com.netflix.astyanax.Serializer;
import com.netflix.astyanax.serializers.PrefixedSerializer;
import com.netflix.astyanax.serializers.ByteBufferSerializer;
/**
* Mapper from a field to a ByteBuffer
* @author elandau
*
* @param <T>
*/
public class FieldMapper<T> {
final Serializer<T> serializer;
final Field field;
final String name;
final boolean reversed;
enum Order {
ASC,
DESC,
}
public FieldMapper(final Field field) {
this(field, null);
}
public FieldMapper(final Field field, ByteBuffer prefix) {
if (prefix != null) {
this.serializer = new PrefixedSerializer<ByteBuffer, T>(prefix, ByteBufferSerializer.get(), (Serializer<T>) MappingUtils.getSerializerForField(field));
}
else {
this.serializer = (Serializer<T>) MappingUtils.getSerializerForField(field);
}
this.field = field;
Column columnAnnotation = field.getAnnotation(Column.class);
if (columnAnnotation == null || columnAnnotation.name().isEmpty()) {
name = field.getName();
}
else {
name = columnAnnotation.name();
}
OrderBy orderByAnnotation = field.getAnnotation(OrderBy.class);
if (orderByAnnotation == null) {
reversed = false;
}
else {
Order order = Order.valueOf(orderByAnnotation.value());
reversed = (order == Order.DESC);
}
}
public Serializer<?> getSerializer() {
return serializer;
}
public ByteBuffer toByteBuffer(Object entity) throws IllegalArgumentException, IllegalAccessException {
return serializer.toByteBuffer(getValue(entity));
}
public T fromByteBuffer(ByteBuffer buffer) {
return serializer.fromByteBuffer(buffer);
}
public T getValue(Object entity) throws IllegalArgumentException, IllegalAccessException {
return (T)field.get(entity);
}
public ByteBuffer valueToByteBuffer(Object value) {
return serializer.toByteBuffer((T)value);
}
public void setValue(Object entity, Object value) throws IllegalArgumentException, IllegalAccessException {
field.set(entity, value);
}
public void setField(Object entity, ByteBuffer buffer) throws IllegalArgumentException, IllegalAccessException {
field.set(entity, fromByteBuffer(buffer));
}
public boolean isAscending() {
return reversed == false;
}
public boolean isDescending() {
return reversed == true;
}
public String getName() {
return name;
}
}