net.sf.mmm.util.bean.base.link

Class EntityBeanLink<E extends EntityBean>

java.lang.Object

net.sf.mmm.util.bean.base.link.AbstractLink<E>

net.sf.mmm.util.bean.base.link.EntityBeanLink<E>

Type Parameters:

E - the generic type of the linked EntityBean.

All Implemented Interfaces:

Link<E>

public class EntityBeanLink<E extends EntityBean>
extends AbstractLink<E>

Implementation of AbstractLink based on an already resolved EntityBean.

Since:

8.0.0

Author:

hohwille

Field Summary

Fields

Modifier and Type	Field and Description
private E	bean

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	EntityBeanLink() The constructor (for serialization and strange frameworks).
protected	EntityBeanLink(E bean) The constructor.

Method Summary

Modifier and Type	Method and Description
boolean	equals(Object obj)
Id<E>	getId()
E	getTarget() This method resolves the linked EntityBean. ATTENTION: An Link can be evaluated lazily.
boolean	isResolved()
static <E extends EntityBean> EntityBeanLink<E>	valueOf(E bean)

Methods inherited from class net.sf.mmm.util.bean.base.link.AbstractLink

hashCode, toString

Methods inherited from class java.lang.Object

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

Field Detail

bean

private final E extends EntityBean bean

Constructor Detail

EntityBeanLink

protected EntityBeanLink()

The constructor (for serialization and strange frameworks).

EntityBeanLink

protected EntityBeanLink(E bean)

The constructor.

Parameters:

bean - - see getTarget().

Method Detail

isResolved

public boolean isResolved()

Returns:

true if the link target is already resolved, false otherwise (if Link.getTarget() may trigger lazy loading and could also fail if called without an open transaction).

getId

public Id<E> getId()

Returns:

the unique identifier of the linked bean. When creating new Beans a link may hold a transient EntityBean as target that has no ID assigned, yet. In such case this method will return null.

getTarget

public E getTarget()

Description copied from interface: Link

This method resolves the linked EntityBean.
ATTENTION:
An Link can be evaluated lazily. In such case the first call of this method will resolve the linked EntityBean from the database. That can be a relatively expensive operation and requires an open transaction. Use Link.isResolved() to distinguish and prevent undesired link resolving.
Further, after serialization (e.g. mapping to JSON and back) maybe only the ID was transferred and this link can not be resolved. In that case this method may return null. Please note that id and target can not both be null. In case a link property is empty it will contain null instead of an empty Link so you can always properly distinguish the scenarios.

Returns:

the link target or null if the link can not be resolved.

equals

public boolean equals(Object obj)

Overrides:

equals in class AbstractLink<E extends EntityBean>

valueOf

public static <E extends EntityBean> EntityBeanLink<E> valueOf(E bean)

Type Parameters:

E - the generic type of the linked EntityBean.

Parameters:

bean - the linked EntityBean.

Returns:

the new EntityBeanLink instance.