org.seedstack.business.domain

Class BaseEntity<I>

java.lang.Object

org.seedstack.business.domain.BaseEntity<I>

Type Parameters:

I - The type of the entity identifier.

All Implemented Interfaces:

Entity<I>

Direct Known Subclasses:

BaseAggregateRoot

public abstract class BaseEntity<I>
extends Object
implements Entity<I>

An helper base class that can be extended to create a domain entity. If extending this base class is not desirable, you can instead do one of the following:

• Implement Entity,
• Annotate your class with DomainEntity (but this limits the ability to use framework features).

This base class provides equals(Object) and hashCode() methods based on the entity identity. It also provides auto-detection of the identity field by reflection (see getId()).

Constructor Summary

Constructors

Constructor and Description
BaseEntity()

Method Summary

Modifier and Type	Method and Description
boolean	equals(Object other) As per Domain-Driven Design semantics, entity equality must be computed on its identity only, as returned by the Entity.getId() method.
I	getId() Returns the identifier of the entity if present.
int	hashCode() As per Domain-Driven Design semantics, the hash code of an entity must be computed on its identity only, as return by as returned by the Entity.getId() method.
String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

BaseEntity

public BaseEntity()

Method Detail

getId

public I getId()

Returns the identifier of the entity if present. Starting from the current class and going up in the hierarchy, this method tries to find:

• A field annotated with Identity,
• Then if not found, a field named "id".

If the entity the identity field does not satisfy any of the conditions above, this method must be overridden to return the entity identity value.

Specified by:

getId in interface Entity<I>

Returns:

the value of the identity field if found, null otherwise.

hashCode

public int hashCode()

Description copied from interface: Entity

As per Domain-Driven Design semantics, the hash code of an entity must be computed on its identity only, as return by as returned by the Entity.getId() method.

Specified by:

hashCode in interface Entity<I>

Overrides:

hashCode in class Object

Returns:

a hash code value for this entity.

equals

public boolean equals(Object other)

Description copied from interface: Entity

As per Domain-Driven Design semantics, entity equality must be computed on its identity only, as returned by the Entity.getId() method. Two entities from the same class hierarchy (with an inheritance relationship between them) can be checked for equality as they have a comparable identity.

When implementing this method for entities, the semantics above must be respected in addition to the semantics of Object.equals(Object).

Specified by:

equals in interface Entity<I>

Overrides:

equals in class Object

Parameters:

other - other object

Returns:

true if the other object is an entity of the same class hierarchy as this entity and has an identity equal to this entity identity.

toString

public String toString()

Overrides:

toString in class Object