com.datastax.driver.extras.codecs.enums.EnumOrdinalCodec Maven / Gradle / Ivy
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/*
* Copyright DataStax, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.datastax.driver.extras.codecs.enums;
import com.datastax.driver.core.ProtocolVersion;
import com.datastax.driver.core.TypeCodec;
import com.datastax.driver.core.exceptions.InvalidTypeException;
import java.nio.ByteBuffer;
/**
* A codec that serializes {@link Enum} instances as CQL {@code int}s representing their ordinal
* values as returned by {@link Enum#ordinal()}.
*
* Note that this codec relies on the enum constants declaration order; it is therefore
* vital that this order remains immutable.
*
* @param The Enum class this codec serializes from and deserializes to.
*/
public class EnumOrdinalCodec> extends TypeCodec {
private final E[] enumConstants;
private final TypeCodec innerCodec;
public EnumOrdinalCodec(Class enumClass) {
this(TypeCodec.cint(), enumClass);
}
public EnumOrdinalCodec(TypeCodec innerCodec, Class enumClass) {
super(innerCodec.getCqlType(), enumClass);
this.enumConstants = enumClass.getEnumConstants();
this.innerCodec = innerCodec;
}
@Override
public ByteBuffer serialize(E value, ProtocolVersion protocolVersion)
throws InvalidTypeException {
return innerCodec.serialize(value == null ? null : value.ordinal(), protocolVersion);
}
@Override
public E deserialize(ByteBuffer bytes, ProtocolVersion protocolVersion)
throws InvalidTypeException {
Integer ordinal = innerCodec.deserialize(bytes, protocolVersion);
if (ordinal == null) return null;
return enumConstants[ordinal];
}
@Override
public E parse(String value) throws InvalidTypeException {
return value == null || value.isEmpty() || value.equalsIgnoreCase("NULL")
? null
: enumConstants[Integer.parseInt(value)];
}
@Override
public String format(E value) throws InvalidTypeException {
if (value == null) return "NULL";
return Integer.toString(value.ordinal());
}
}