/*
* Copyright (c) 2005-2016 Vincent Vandenschrick. All rights reserved.
*
* This file is part of the Jspresso framework.
*
* Jspresso is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Jspresso is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with Jspresso. If not, see <http://www.gnu.org/licenses/>.
*/
package org.jspresso.framework.model.entity;
import java.io.Serializable;
import org.jspresso.framework.model.component.IComponent;
/**
* This interface must be implemented by all persistent entities in the
* application domain. It establishes the minimal contract of an entity which is
* providing id accessors.
*
* @author Vincent Vandenschrick
*/
public interface IEntity extends IComponent {
/**
* constant for identifier property {@code ID}.
*/
String ID = "id";
/**
* constant for version property {@code VERSION}.
*/
String VERSION = "version";
/**
* {@code DELETED_VERSION} is a magic constant for deleted entities.
*/
Integer DELETED_VERSION = -Integer.MAX_VALUE;
/**
* constant for version property {@code PERSISTENT}.
*/
String PERSISTENT = "persistent";
/**
* It is important to declare here so that ORM (hibernate for instance)
* detects it has to delegate to the underlying instance when proxiing.
*
* @param o
* the instance to compare to.
* @return true if both instances are equal.
*/
@Override
boolean equals(Object o);
/**
* Gets the interface or class establishing the entity contract.
*
* @return the entity contract.
*/
@Override
Class<? extends IEntity> getComponentContract();
/**
* Gets the id used to uniquely identify an entity (surrogate key). The id is
* assigned to the entity instance as soon as the entity is created in memory
* an is afterwards made immutable so that {@code equals()} and
* {@code hashCode()} can safely rely on it whenever they are transient
* or not. It also establishes the minimal contract of a versionable entity
* which is providing version accessors to handle access concurrency.
*
* @return The id of the entity.
*/
Serializable getId();
/**
* Gets the version of this entity.
*
* @return the entity version.
*/
Integer getVersion();
/**
* Sets the version of this entity.
*
* @param version
* the entity version.
*/
void setVersion(Integer version);
/**
* It is important to declare here so that ORM (hibernate for instance)
* detects it has to delegate to the underlying instance when proxiing.
*
* @return the hashcode.
*/
@Override
int hashCode();
/**
* Gets whether this entity has already been saved in the backing store.
*
* @return true if the entity is not transient.
*/
boolean isPersistent();
}