Module java.prefs
Package java.util.prefs

## Class PreferenceChangeEvent

- java.lang.Object
- - java.util.EventObject
  - - java.util.prefs.PreferenceChangeEvent

- All Implemented Interfaces:
    `Serializable`

      public class PreferenceChangeEvent
      extends EventObject

  An event emitted by a `Preferences` node to indicate that a preference has been added, removed or has had its value changed.

  Note, that although PreferenceChangeEvent inherits Serializable interface from EventObject, it is not intended to be Serializable. Appropriate serialization methods are implemented to throw NotSerializableException.

  Since:
    1.4
  See Also:
    `Preferences`, `PreferenceChangeListener`, `NodeChangeEvent`

- - ### Field Summary

    - ### Fields declared in class java.util.EventObject

      `source`

  - ### Constructor Summary

    Constructors
    Constructor | Description
    --- | ---
    `PreferenceChangeEvent​(Preferences node, String key, String newValue)` | Constructs a new `PreferenceChangeEvent` instance.

  - ### Method Summary

    Modifier and Type | Method | Description
    --- | --- | ---
    `String` | `getKey()` | Returns the key of the preference that was changed.
    `String` | `getNewValue()` | Returns the new value for the preference.
    `Preferences` | `getNode()` | Returns the preference node that emitted the event.

    - ### Methods declared in class java.util.EventObject

      `getSource, toString`

    - ### Methods declared in class java.lang.Object

      `clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait`

- - ### Constructor Detail

    - #### PreferenceChangeEvent

          public PreferenceChangeEvent​(Preferences node,
                                       String key,
                                       String newValue)

      Constructs a new `PreferenceChangeEvent` instance.
      Parameters:
        `node` - The Preferences node that emitted the event.
        `key` - The key of the preference that was changed.
        `newValue` - The new value of the preference, or `null` if the preference is being removed.

  - ### Method Detail

    - #### getNode

          public Preferences getNode()

      Returns the preference node that emitted the event.
      Returns:
        The preference node that emitted the event.

    - #### getKey

          public String getKey()

      Returns the key of the preference that was changed.
      Returns:
        The key of the preference that was changed.

    - #### getNewValue

          public String getNewValue()

      Returns the new value for the preference.
      Returns:
        The new value for the preference, or `null` if the preference was removed.