Class LinkedHashMap<K,V>

java.lang.Object
java.util.AbstractMap<K,V>
java.util.HashMap<K,V>
java.util.LinkedHashMap<K,V>
org.datanucleus.store.types.wrappers.LinkedHashMap<K,V>
org.datanucleus.store.types.wrappers.backed.LinkedHashMap<K,V>
All Implemented Interfaces:
Serializable, Cloneable, Map<K,V>, SCO<LinkedHashMap<K,V>>, SCOContainer<LinkedHashMap<K,V>>, SCOMap<LinkedHashMap<K,V>, K, V>, BackedSCO
public class LinkedHashMap<K,V> extends LinkedHashMap<K,V> implements BackedSCO
A mutable second-class LinkedHashMap object. Backed by a MapStore object.
See Also:

  • Field Details

    • allowNulls

      protected transient boolean allowNulls

    • backingStore

      protected transient MapStore<K,V> backingStore

    • useCache

      protected transient boolean useCache

    • isCacheLoaded

      protected transient boolean isCacheLoaded

  • Constructor Details

  • Method Details

    • initialise

      public void initialise(LinkedHashMap newValue, Object oldValue)
      Description copied from interface: SCO
      Method to initialise the SCO for use, where replacing an old value with a new value such as when calling a setter field passing in a new value. Note that oldValue is marked as Object since for cases where the member type is Collection the newValue could be, for example, ArrayList, and the oldValue of type Collection (representing null).
      Specified by:
      initialise in interface SCO<K>
      Overrides:
      initialise in class LinkedHashMap<K,V>
      Parameters:
      newValue - New value (to wrap)
      oldValue - Old value (to use in deciding what needs deleting etc)

    • initialise

      public void initialise(LinkedHashMap m)
      Method to initialise the SCO from an existing value.
      Specified by:
      initialise in interface SCO<K>
      Overrides:
      initialise in class LinkedHashMap<K,V>
      Parameters:
      m - Object to set value using.

    • initialise

      public void initialise()
      Method to initialise the SCO for use.
      Specified by:
      initialise in interface SCO<K>
      Overrides:
      initialise in class LinkedHashMap<K,V>

    • getValue

      public LinkedHashMap getValue()
      Accessor for the unwrapped value that we are wrapping.
      Specified by:
      getValue in interface SCO<K>
      Overrides:
      getValue in class LinkedHashMap<K,V>
      Returns:
      The unwrapped value

    • load

      public void load()
      Method to effect the load of the data in the SCO. Used when the SCO supports lazy-loading to tell it to load all now.
      Specified by:
      load in interface SCOContainer<K>
      Overrides:
      load in class LinkedHashMap<K,V>

    • isLoaded

      public boolean isLoaded()
      Method to return if the SCO has its contents loaded. If the SCO doesn't support lazy loading will just return true.
      Specified by:
      isLoaded in interface BackedSCO
      Specified by:
      isLoaded in interface SCOContainer<K>
      Overrides:
      isLoaded in class LinkedHashMap<K,V>
      Returns:
      Whether it is loaded

    • loadFromStore

      protected void loadFromStore()
      Method to load all elements from the "backing store" where appropriate.

    • getBackingStore

      public Store getBackingStore()
      Specified by:
      getBackingStore in interface BackedSCO

    • updateEmbeddedKey

      public void updateEmbeddedKey(K key, int fieldNumber, Object newValue, boolean makeDirty)
      Method to update an embedded key in this map.
      Specified by:
      updateEmbeddedKey in interface SCOMap<LinkedHashMap<K,V>, K, V>
      Overrides:
      updateEmbeddedKey in class LinkedHashMap<K,V>
      Parameters:
      key - The key
      fieldNumber - Number of field in the key
      newValue - New value for this field
      makeDirty - Whether to make the SCO field dirty.

    • updateEmbeddedValue

      public void updateEmbeddedValue(V value, int fieldNumber, Object newValue, boolean makeDirty)
      Method to update an embedded value in this map.
      Specified by:
      updateEmbeddedValue in interface SCOMap<LinkedHashMap<K,V>, K, V>
      Overrides:
      updateEmbeddedValue in class LinkedHashMap<K,V>
      Parameters:
      value - The value
      fieldNumber - Number of field in the value
      newValue - New value for this field
      makeDirty - Whether to make the SCO field dirty.

    • unsetOwner

      public void unsetOwner()
      Method to unset the owner and field details.
      Specified by:
      unsetOwner in interface SCO<K>
      Overrides:
      unsetOwner in class LinkedHashMap<K,V>

    • clone

      public Object clone()
      Creates and returns a copy of this object.

      Mutable second-class Objects are required to provide a public clone method in order to allow for copying persistable objects. In contrast to Object.clone(), this method must not throw a CloneNotSupportedException.

      Specified by:
      clone in interface SCO<K>
      Overrides:
      clone in class LinkedHashMap<K,V>
      Returns:
      The cloned object

    • containsKey

      public boolean containsKey(Object key)
      Method to return if the map contains this key
      Specified by:
      containsKey in interface Map<K,V>
      Overrides:
      containsKey in class LinkedHashMap<K,V>
      Parameters:
      key - The key
      Returns:
      Whether it is contained

    • containsValue

      public boolean containsValue(Object value)
      Method to return if the map contains this value.
      Specified by:
      containsValue in interface Map<K,V>
      Overrides:
      containsValue in class LinkedHashMap<K,V>
      Parameters:
      value - The value
      Returns:
      Whether it is contained

    • entrySet

      public Set entrySet()
      Accessor for the set of entries in the Map.
      Specified by:
      entrySet in interface Map<K,V>
      Overrides:
      entrySet in class LinkedHashMap<K,V>
      Returns:
      Set of entries

    • equals

      public boolean equals(Object o)
      Method to check the equality of this map, and another.
      Specified by:
      equals in interface Map<K,V>
      Overrides:
      equals in class LinkedHashMap<K,V>
      Parameters:
      o - The map to compare against.
      Returns:
      Whether they are equal.

    • forEach

      public void forEach(BiConsumer<? super K, ? super V> action)
      Specified by:
      forEach in interface Map<K,V>
      Overrides:
      forEach in class LinkedHashMap<K,V>

    • get

      public V get(Object key)
      Accessor for the value stored against a key.
      Specified by:
      get in interface Map<K,V>
      Overrides:
      get in class LinkedHashMap<K,V>
      Parameters:
      key - The key
      Returns:
      The value.

    • hashCode

      public int hashCode()
      Method to generate a hashcode for this Map.
      Specified by:
      hashCode in interface Map<K,V>
      Overrides:
      hashCode in class LinkedHashMap<K,V>
      Returns:
      The hashcode.

    • isEmpty

      public boolean isEmpty()
      Method to return if the Map is empty.
      Specified by:
      isEmpty in interface Map<K,V>
      Overrides:
      isEmpty in class LinkedHashMap<K,V>
      Returns:
      Whether it is empty.

    • keySet

      public Set keySet()
      Accessor for the set of keys in the Map.
      Specified by:
      keySet in interface Map<K,V>
      Overrides:
      keySet in class LinkedHashMap<K,V>
      Returns:
      Set of keys.

    • size

      public int size()
      Method to return the size of the Map.
      Specified by:
      size in interface Map<K,V>
      Overrides:
      size in class LinkedHashMap<K,V>
      Returns:
      The size

    • values

      public Collection values()
      Accessor for the set of values in the Map.
      Specified by:
      values in interface Map<K,V>
      Overrides:
      values in class LinkedHashMap<K,V>
      Returns:
      Set of values.

    • clear

      public void clear()
      Method to clear the LinkedHashMap.
      Specified by:
      clear in interface Map<K,V>
      Overrides:
      clear in class LinkedHashMap<K,V>

    • put

      public V put(K key, V value)
      Method to add a value against a key to the LinkedHashMap.
      Specified by:
      put in interface Map<K,V>
      Overrides:
      put in class LinkedHashMap<K,V>
      Parameters:
      key - The key
      value - The value
      Returns:
      The previous value for the specified key.

    • putAll

      public void putAll(Map m)
      Method to add the specified Map's values under their keys here.
      Specified by:
      putAll in interface Map<K,V>
      Overrides:
      putAll in class LinkedHashMap<K,V>
      Parameters:
      m - The map

    • remove

      public V remove(Object key)
      Method to remove the value for a key from the LinkedHashMap.
      Specified by:
      remove in interface Map<K,V>
      Overrides:
      remove in class LinkedHashMap<K,V>
      Parameters:
      key - The key to remove
      Returns:
      The value that was removed from this key.

    • writeReplace

      protected Object writeReplace() throws ObjectStreamException
      The writeReplace method is called when ObjectOutputStream is preparing to write the object to the stream. The ObjectOutputStream checks whether the class defines the writeReplace method. If the method is defined, the writeReplace method is called to allow the object to designate its replacement in the stream. The object returned should be either of the same type as the object passed in or an object that when read and resolved will result in an object of a type that is compatible with all references to the object.
      Overrides:
      writeReplace in class LinkedHashMap<K,V>
      Returns:
      the replaced object
      Throws:
      ObjectStreamException - if an error occurs