io.objectbox.relation

Class ToOne<TARGET>

java.lang.Object

io.objectbox.relation.ToOne<TARGET>

All Implemented Interfaces:

java.io.Serializable

public class ToOne<TARGET>
extends java.lang.Object
implements java.io.Serializable

Manages a to-one relation: resolves the target object, keeps the target Id in sync, etc. A to-relation is unidirectional: it points from the source entity to the target entity. The target is referenced by its ID, which is persisted in the source entity.

If there is a ToMany relation linking back to this to-one relation (@Backlink), the ToMany object will not be notified/updated about persisted changes here. Call ToMany.reset() so it will update when next accessed.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
ToOne(java.lang.Object sourceEntity, RelationInfo<?,TARGET> relationInfo) In Java, the constructor call is generated by the ObjectBox plugin.

Method Summary

Modifier and Type	Method and Description
boolean	equals(java.lang.Object obj)
TARGET	getCachedTarget()
TARGET	getTarget()
TARGET	getTarget(long targetId) If property backed, entities can pass the target ID to avoid reflection.
long	getTargetId()
int	hashCode()
void	internalPutTarget(io.objectbox.Cursor<TARGET> targetCursor)
boolean	internalRequiresPutTarget()
boolean	isNull()
boolean	isResolved()
boolean	isResolvedAndNotNull()
void	setAndPutTarget(TARGET target) Sets or clears the target entity and ID in the source entity, then puts the source entity to persist changes.
void	setAndPutTargetAlways(TARGET target) Sets or clears the target entity and ID in the source entity, then puts the target (if not null) and source entity to persist changes.
void	setTarget(TARGET target) Sets or clears the target entity and ID in the source entity.
void	setTargetId(long targetId) Sets or clears the target ID in the source entity.

Methods inherited from class java.lang.Object

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

Constructor Detail

ToOne

public ToOne(java.lang.Object sourceEntity,
             RelationInfo<?,TARGET> relationInfo)

In Java, the constructor call is generated by the ObjectBox plugin.

Parameters:

sourceEntity - The source entity that owns the to-one relation.

relationInfo - Meta info as generated in the Entity_ (entity name plus underscore) classes.

Method Detail

getTarget

public TARGET getTarget()

Returns:

The target entity of the to-one relation.

getTarget

@Internal
public TARGET getTarget(long targetId)

If property backed, entities can pass the target ID to avoid reflection.

getCachedTarget

public TARGET getCachedTarget()

isResolved

public boolean isResolved()

isResolvedAndNotNull

public boolean isResolvedAndNotNull()

isNull

public boolean isNull()

setTargetId

public void setTargetId(long targetId)

Sets or clears the target ID in the source entity. Pass 0 to clear.

Put the source entity to persist changes. If the ID is not 0 creates a relation to the target entity with this ID, otherwise dissolves it.

See Also:

setTarget(TARGET)

setTarget

public void setTarget(@Nullable
                      TARGET target)

Sets or clears the target entity and ID in the source entity. Pass null to clear.

Put the source entity to persist changes. If the target entity was not put yet (its ID is 0), it will be stored when the source entity is put.

See Also:

setTargetId(long)

setAndPutTarget

public void setAndPutTarget(@Nullable
                            TARGET target)

Sets or clears the target entity and ID in the source entity, then puts the source entity to persist changes. Pass null to clear.

If the target entity was not put yet (its ID is 0), it will be put before the source entity.

setAndPutTargetAlways

public void setAndPutTargetAlways(@Nullable
                                  TARGET target)

Sets or clears the target entity and ID in the source entity, then puts the target (if not null) and source entity to persist changes. Pass null to clear.

When clearing the target entity, this does not remove it from its box. This only dissolves the relation.

getTargetId

public long getTargetId()

internalRequiresPutTarget

@Internal
public boolean internalRequiresPutTarget()

internalPutTarget

@Internal
public void internalPutTarget(io.objectbox.Cursor<TARGET> targetCursor)

equals

public boolean equals(java.lang.Object obj)

Overrides:

equals in class java.lang.Object

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object