com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBAutoGeneratedDefault Maven / Gradle / Ivy
/*
* Copyright 2016-2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* 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://aws.amazon.com/apache2.0
*
* This file 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.amazonaws.services.dynamodbv2.datamodeling;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
/**
* Annotation to assign a default value on creation if value is null.
*
*
* @DynamoDBAutoGeneratedDefault("OPEN")
* public String getStatus()
*
*
* Only compatible with standard string types.
*
*/
@DynamoDB
@DynamoDBAutoGenerated(generator=DynamoDBAutoGeneratedDefault.Generator.class)
@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.FIELD, ElementType.METHOD})
public @interface DynamoDBAutoGeneratedDefault {
/**
* The default value.
*/
String value();
/**
* Default generator.
*/
static final class Generator extends DynamoDBAutoGenerator.AbstractGenerator {
private final DynamoDBTypeConverter converter;
private final String defaultValue;
public Generator(Class targetType, DynamoDBAutoGeneratedDefault annotation) {
super(DynamoDBAutoGenerateStrategy.CREATE);
this.converter = StandardTypeConverters.factory().getConverter(targetType, String.class);
this.defaultValue = annotation.value();
}
@Override
public final T generate(T currentValue) {
return converter.convert(defaultValue);
}
}
}