com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBVersionAttribute Maven / Gradle / Ivy
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/*
* Copyright 2011-2020 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 for marking a property as an optimistic locking version attribute.
*
* Applied to the getter method or the class field for the class's version
* property. If the annotation is applied directly to the class field, the
* corresponding getter and setter must be declared in the same class.
*
*
Alternately, the meta-annotation {@link DynamoDBVersioned} may be used
* to annotate a custom annotation, or directly to the field/getter.
*
* Only nullable, integral numeric types (e.g. Integer, Long) can be used as
* version properties. On a save() operation, the {@link DynamoDBMapper} will
* attempt to increment the version property and assert that the service's value
* matches the client's. New objects will be assigned a version of 1 when saved.
* Note that for batchWrite, and by extension batchSave and batchDelete, no
* version checks are performed, as required by the
* {@link com.amazonaws.services.dynamodbv2.AmazonDynamoDB#batchWriteItem(BatchWriteItemRequest)}
* API.
*
* @see com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBVersioned
*/
@DynamoDB
@DynamoDBVersioned
@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.FIELD, ElementType.METHOD})
public @interface DynamoDBVersionAttribute {
/**
* Optional parameter when the name of the attribute as stored in DynamoDB
* should differ from the name used by the getter / setter.
*/
String attributeName() default "";
}