java.lang.Object
- io.github.mmm.entity.link.AbstractLink<E>
- - io.github.mmm.entity.link.IdLink<E>

Type Parameters:

E - the generic type of the linked entity.

All Implemented Interfaces:

Link<E>
```
public class IdLink<E>
extends AbstractLink<E>
```
Implementation of Link that carries the Id of an entity. It optionally allows lazy loading on the first call of getTarget() via an externally given resolver Function. This approach is easier, less invasive and more lightweight as using proxy objects for entities.

Since:

1.0.0

Constructor Summary

Constructors
Modifier Constructor Description

protected IdLink(Id<E> id, Function<Id<E>,E> resolver)
The constructor.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`Id<E>`	`getId()`
`E`	`getTarget()`	This method resolves the linked entity. ATTENTION: A `Link` can be evaluated lazily.
`boolean`	`isResolved()`
`static <E> IdLink<E>`	`of(Id<E> id, Function<Id<E>,E> resolver)`
`IdLink<E>`	`withType(Class<?> type)`

Methods inherited from class io.github.mmm.entity.link.AbstractLink
equals, hashCode, toString

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

- Constructor Detail
  - IdLink
```
protected IdLink(Id<E> id,
                 Function<Id<E>,E> resolver)
```
    The constructor.
    
    Parameters:
    
    id - - see getId().
    
    resolver - the Function to resolve the link target (the entity).
- Method Detail
  - getId
```
public Id<E> getId()
```
    Returns:
    
    the unique identifier of the linked bean. When creating new Entities a link may hold a transient Entity as target that has no ID assigned, yet. In such case this method will return null.
  - 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).
  - getTarget
```
public E getTarget()
```
    Description copied from interface: Link
    
    This method resolves the linked entity.
    ATTENTION:
    A Link can be evaluated lazily. In such case the first call of this method will resolve the linked entity 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.
  - withType
```
public IdLink<E> withType(Class<?> type)
```
    Parameters:
    
    type - the new value of Id.getType(). Exact type should actually be Class<E> but this prevents simple usage.
    
    Returns:
    
    a copy of this Link with the given type or this Link itself if already satisfying.
    
    See Also:
    
    Id.withType(Class)
  - of
```
public static <E> IdLink<E> of(Id<E> id,
                               Function<Id<E>,E> resolver)
```
    Type Parameters:
    
    E - type of the linked Entity.
    
    Parameters:
    
    id - the id.
    
    resolver - the Function to resolve the Id.
    
    Returns:
    
    the IdLink instance.

Class IdLink<E>

Constructor Summary

Method Summary

Methods inherited from class io.github.mmm.entity.link.AbstractLink

Methods inherited from class java.lang.Object

Constructor Detail

IdLink

Method Detail

getId

isResolved

getTarget

withType

of