io.realm

Class RealmList<E extends RealmObject>

java.lang.Object

java.util.AbstractCollection<E>

java.util.AbstractList<E>

io.realm.RealmList<E>

Type Parameters:

E - The class of objects in list.

All Implemented Interfaces:

java.lang.Iterable<E>, java.util.Collection<E>, java.util.List<E>

public class RealmList<E extends RealmObject>
extends java.util.AbstractList<E>

RealmList is used to model one-to-many relationships in a RealmObject. RealmList has two modes: A managed and non-managed mode. In managed mode all objects are persisted inside a Realm, in non-managed mode it works as a normal ArrayList.

Only Realm can create managed RealmLists. Managed RealmLists will automatically update the content whenever the underlying Realm is updated, and can only be accessed using the getter of a RealmObject.

Non-managed RealmLists can be created by the user and can contain both managed and non-managed RealmObjects. This is useful when dealing with JSON deserializers like GSON or other frameworks that inject values into a class. Non-managed elements in this list can be added to a Realm using the Realm.copyToRealm(Iterable) method.

Field Summary

Fields inherited from class java.util.AbstractList

modCount

Constructor Summary

Constructors

Constructor and Description
RealmList() Create a RealmList in non-managed mode, where the elements are not controlled by a Realm.
RealmList(E... objects) Create a RealmList in non-managed mode with an initial list of elements.

Method Summary

Modifier and Type	Method and Description
boolean	add(E object) Adds the specified object at the end of this List.
void	add(int location, E object) Inserts the specified object into this List at the specified location.
void	clear()
E	first() Find the first object.
E	get(int location)
E	last() Find the last object.
void	move(int oldPos, int newPos) Moves an object from one position to another, while maintaining a fixed sized list.
E	remove(int location)
E	set(int location, E object) Replaces the element at the specified location in this list with the specified object.
int	size()
java.lang.String	toString()
RealmQuery<E>	where() Returns a RealmQuery, which can be used to query for specific objects of this class

Methods inherited from class java.util.AbstractList

addAll, equals, hashCode, indexOf, iterator, lastIndexOf, listIterator, listIterator, removeRange, subList

Methods inherited from class java.util.AbstractCollection

addAll, contains, containsAll, isEmpty, remove, removeAll, retainAll, toArray, toArray

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.List

addAll, contains, containsAll, isEmpty, remove, removeAll, replaceAll, retainAll, sort, spliterator, toArray, toArray

Methods inherited from interface java.util.Collection

parallelStream, removeIf, stream

Methods inherited from interface java.lang.Iterable

forEach

Constructor Detail

RealmList

public RealmList()

Create a RealmList in non-managed mode, where the elements are not controlled by a Realm. This effectively makes the RealmList function as a ArrayList and it is not possible to query the objects in this state.

Use Realm.copyToRealm(Iterable) to properly persist it's elements in Realm.

RealmList

public RealmList(E... objects)

Create a RealmList in non-managed mode with an initial list of elements. A RealmList in non-managed mode function as a ArrayList and it is not possible to query the objects in this state. Use Realm.copyToRealm(Iterable) to properly persist all non-managed elements in Realm.

Parameters:

objects - Initial objects in the list.

Method Detail

add

public void add(int location,
                E object)

Inserts the specified object into this List at the specified location. The object is inserted before any previous element at the specified location. If the location is equal to the size of this List, the object is added at the end.

1. Un-managed RealmLists: It is possible to add both managed and un-managed objects. If adding managed objects to a un-managed RealmList they will not be copied to the Realm again if using Realm.copyToRealm(RealmObject) afterwards.
2. Managed RealmLists: It is possible to add un-managed objects to a RealmList that is already managed. In that case the object will transparently be copied to Realm using Realm.copyToRealm(RealmObject) or Realm.copyToRealmOrUpdate(RealmObject) if it has a primary key.

Specified by:

add in interface java.util.List<E extends RealmObject>

Overrides:

add in class java.util.AbstractList<E extends RealmObject>

Parameters:

location - the index at which to insert.

object - the object to add.

Throws:

java.lang.IndexOutOfBoundsException - if location < 0 || location > size()

add

public boolean add(E object)

Adds the specified object at the end of this List.

1. Un-managed RealmLists: It is possible to add both managed and un-managed objects. If adding managed objects to a un-managed RealmList they will not be copied to the Realm again if using Realm.copyToRealm(RealmObject) afterwards.
2. Managed RealmLists: It is possible to add un-managed objects to a RealmList that is already managed. In that case the object will transparently be copied to Realm using Realm.copyToRealm(RealmObject) or Realm.copyToRealmOrUpdate(RealmObject) if it has a primary key.

Specified by:

add in interface java.util.Collection<E extends RealmObject>

Specified by:

add in interface java.util.List<E extends RealmObject>

Overrides:

add in class java.util.AbstractList<E extends RealmObject>

Parameters:

object - the object to add.

Returns:

true

set

public E set(int location,
             E object)

Replaces the element at the specified location in this list with the specified object.

1. Un-managed RealmLists: It is possible to add both managed and un-managed objects. If adding managed objects to a un-managed RealmList they will not be copied to the Realm again if using Realm.copyToRealm(RealmObject) afterwards.
2. Managed RealmLists: It is possible to add un-managed objects to a RealmList that is already managed. In that case the object will transparently be copied to Realm using Realm.copyToRealm(RealmObject) or Realm.copyToRealmOrUpdate(RealmObject) if it has a primary key.

Specified by:

set in interface java.util.List<E extends RealmObject>

Overrides:

set in class java.util.AbstractList<E extends RealmObject>

Parameters:

location - the index at which to put the specified object.

object - the object to add.

Returns:

the previous element at the index.

Throws:

java.lang.IndexOutOfBoundsException - if location < 0 || location >= size()

move

public void move(int oldPos,
                 int newPos)

Moves an object from one position to another, while maintaining a fixed sized list. RealmObjects will be shifted so no null values are introduced.

Parameters:

oldPos - Index of RealmObject to move.

newPos - Target position. If newPos < oldPos the object at the location will be shifted to the right. If oldPos < newPos, indexes > oldPos will be shifted once to the left.

Throws:

java.lang.IndexOutOfBoundsException - if any position is outside [0, size()[.

clear

public void clear()

Specified by:

clear in interface java.util.Collection<E extends RealmObject>

Specified by:

clear in interface java.util.List<E extends RealmObject>

Overrides:

clear in class java.util.AbstractList<E extends RealmObject>

remove

public E remove(int location)

Specified by:

remove in interface java.util.List<E extends RealmObject>

Overrides:

remove in class java.util.AbstractList<E extends RealmObject>

get

public E get(int location)

Specified by:

get in interface java.util.List<E extends RealmObject>

Specified by:

get in class java.util.AbstractList<E extends RealmObject>

first

public E first()

Find the first object.

Returns:

The first object or null if the list is empty.

last

public E last()

Find the last object.

Returns:

The last object or null if the list is empty.

size

public int size()

Specified by:

size in interface java.util.Collection<E extends RealmObject>

Specified by:

size in interface java.util.List<E extends RealmObject>

Specified by:

size in class java.util.AbstractCollection<E extends RealmObject>

where

public RealmQuery<E> where()

Returns a RealmQuery, which can be used to query for specific objects of this class

Returns:

A RealmQuery object

See Also:

RealmQuery

toString

public java.lang.String toString()

Overrides:

toString in class java.util.AbstractCollection<E extends RealmObject>