org.jmolecules.ddd.annotation.AggregateRoot.kt Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of kmolecules-ddd Show documentation

Kotlin flavor of jMolecules DDD

The newest version!

/*
 * Copyright 2022-2023 the original author or authors.
 *
 * 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 org.jmolecules.ddd.annotation

/**
 * Identifies an aggregate root, i.e. the root entity of an aggregate. An aggregate forms a cluster of consistent rules
 * usually formed around a set of entities by defining invariants based on the properties of the aggregate that have to
 * be met before and after operations on it. Aggregates usually refer to other aggregates by their identifier.
 * References to aggregate internals should be avoided and at least not considered strongly consistent (i.e. a reference
 * held could possibly have been gone or become invalid at any point in time). They also act as scope of consistency,
 * i.e. changes on a single aggregate are expected to be strongly consistent while changes across multiple ones should
 * only expect eventual consistency.
 *
 * Kotlin's counterpart of the Java's [AggregateRoot](https://github.com/xmolecules/jmolecules/blob/main/jmolecules-ddd/src/main/java/org/jmolecules/ddd/annotation/AggregateRoot.java)
 *
 * @author Jocelyn Ntakpe
 *
 * See also : [Domain-Driven Design Reference (Evans) - Aggregates](https://domainlanguage.com/wp-content/uploads/2016/05/DDD_Reference_2015-03.pdf)
 */
@Entity
@Retention
@MustBeDocumented
@Target(AnnotationTarget.CLASS)
annotation class AggregateRoot