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io.realm

Class RealmMap

On this page

  • io.realm
  • Method Summary
  • Inherited Methods
  • Method Detail
  • addChangeListener
  • clear
  • containsKey
  • containsValue
  • entrySet
  • freeze
  • get
  • isEmpty
  • isFrozen
  • isManaged
  • isValid
  • keySet
  • put
  • putAll
  • remove
  • removeAllChangeListeners
  • removeChangeListener
  • size
  • values

io.realm

java.lang.Object
io.realm.RealmMap

Implemented interfaces:

  • java.util.Map

RealmMap is used to map keys to values. A RealmMap cannot contain duplicate keys and each key can map to at most one value. A RealmMap cannot have null keys but can have null values.

Similarly to RealmList s, a RealmDictionary can operate in managed and unmanaged modes. In managed mode a RealmDictionary persists all its contents inside a Realm whereas in unmanaged mode it functions like a HashMap .

Managed RealmDictionaries can only be created by Realm and will automatically update its content whenever the underlying Realm is updated. Managed RealmDictionaries can only be accessed using the getter that points to a RealmDictionary field of a RealmObject .

Unmanaged RealmDictionaries can be created by the user and can contain both managed and unmanaged RealmObjects. This is useful when dealing with JSON deserializers like GSON or other frameworks that inject values into a class. Unmanaged RealmMaps can be added to a Realm using the Realm.copyToRealm(Iterable, ImportFlag...) method.

Method Summary

Modifier and Type
Method and Description
public void
public void
addChangeListener (
io.realm.MapChangeListener<K, V> listener
)

Adds a change listener to this RealmMap .

public void
public boolean
public boolean
public Set
public RealmMap
public V
get (
Object key
)
public boolean
public boolean
public boolean
public boolean
public Set
public V
put (
K key,
V value
)
public void
public V
public void
removeAllChangeListeners ()

Removes all user-defined change listeners.

public void
removeChangeListener (
io.realm.RealmChangeListener<io.realm.RealmMap<K, V>> listener
)

Removes the specified change listener.

public void
removeChangeListener (
io.realm.MapChangeListener<K, V> listener
)

Removes the specified change listener.

public int
size ()

public Collection

Inherited Methods

  • Methods inherited from class java.lang.Object : getClass , hashCode , equals , clone , toString , notify , notifyAll , wait , wait , wait , finalize

Method Detail

addChangeListener

Adds a change listener to this RealmMap .

Registering a change listener will not prevent the underlying RealmMap from being garbage collected. If the RealmMap is garbage collected, the change listener will stop being triggered. To avoid this, keep a strong reference for as long as appropriate e.g. in a class variable.

public class MyActivity extends Activity {
    private RealmMap<String, Dog> dogs; // Strong reference to keep listeners alive
    @Override
    protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      dogs = realm.where(Person.class).findFirst().getDogs();
      dogs.addChangeListener(new RealmChangeListener<RealmMap<String, Dog>>() {
          @Override
          public void onChange(RealmMap<String, Dog> map) {
              // React to change
          }
      });
    }
}

Parameters

  • listener - the change listener to be notified.

Throws

Tip

See also:

Adds a change listener to this RealmMap .

Registering a change listener will not prevent the underlying RealmMap from being garbage collected. If the RealmMap is garbage collected, the change listener will stop being triggered. To avoid this, keep a strong reference for as long as appropriate e.g. in a class variable.

public class MyActivity extends Activity {
    private RealmMap<String, Dog> dogs; // Strong reference to keep listeners alive
    @Override
    protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      dogs = realm.where(Person.class).findFirst().getDogs();
      dogs.addChangeListener(new MapChangeListener<String, Dog>() {
          @Override
          public void onChange(RealmMap<String, Dog> map, MapChangeSet<String> changeSet) {
              // React to change
          }
      });
    }
}

Parameters

  • listener - the change listener to be notified.

Throws

clear

public void clear ()

containsKey

public boolean containsKey (
Object key
)

containsValue

public boolean containsValue (
Object value
)

entrySet

public Set entrySet ()

freeze

public RealmMap freeze ()

get

public V get (
Object key
)

isEmpty

public boolean isEmpty ()

isFrozen

public boolean isFrozen ()

isManaged

public boolean isManaged ()

isValid

public boolean isValid ()

keySet

public Set keySet ()

put

public V put (
K key,
V value
)

putAll

remove

public V remove (
Object key
)

removeAllChangeListeners

Removes all user-defined change listeners.

Throws

Tip

See also:

removeChangeListener

Removes the specified change listener.

Parameters

  • listener - the change listener to be removed.

Throws

Tip

See also:

Removes the specified change listener.

Parameters

  • listener - the change listener to be removed.

Throws

size

public int size ()

values

public Collection values ()

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