NamespaceChangeListener (Java SE 21 & JDK 21)
Description: declaration: module: java.naming, package: javax.naming.event, interface: NamespaceChangeListener
Keywords: javax.naming.event.NamespaceChangeListener interface

Module java.naming
Package javax.naming.event

# Interface NamespaceChangeListener

All Superinterfaces:
  `EventListener`, `NamingListener`

public interface NamespaceChangeListener extends NamingListener
Specifies the methods that a listener interested in namespace changes must implement. Specifically, the listener is interested in `NamingEvent`s with event types of `OBJECT_ADDED, OBJECT_RENAMED`, or `OBJECT_REMOVED`.

Such a listener must:

1. Implement this interface and its methods.
2. Implement `NamingListener.namingExceptionThrown()` so that it will be notified of exceptions thrown while attempting to collect information about the events.
3. Register with the source using the source's `addNamingListener()` method.

A listener that wants to be notified of `OBJECT_CHANGED` event types should also implement the `ObjectChangeListener` interface.

Since:
  1.3
See Also:
  - `NamingEvent`
  - `ObjectChangeListener`
  - `EventContext`
  - `EventDirContext`

- ## Method Summary

  Modifier and Type
  Method
  Description
  `void`
  `objectAdded(NamingEvent evt)`
  Called when an object has been added.
  `void`
  `objectRemoved(NamingEvent evt)`
  Called when an object has been removed.
  `void`
  `objectRenamed(NamingEvent evt)`
  Called when an object has been renamed.

  ### Methods declared in interface javax.naming.event.NamingListener

  `namingExceptionThrown`

- ## Method Details

  - ### objectAdded

    void objectAdded(NamingEvent evt)
    Called when an object has been added.

    The binding of the newly added object can be obtained using `evt.getNewBinding()`.

    Parameters:
      `evt` - The nonnull event.
    See Also:
      - `NamingEvent.OBJECT_ADDED`

  - ### objectRemoved

    void objectRemoved(NamingEvent evt)
    Called when an object has been removed.

    The binding of the newly removed object can be obtained using `evt.getOldBinding()`.

    Parameters:
      `evt` - The nonnull event.
    See Also:
      - `NamingEvent.OBJECT_REMOVED`

  - ### objectRenamed

    void objectRenamed(NamingEvent evt)
    Called when an object has been renamed.

    The binding of the renamed object can be obtained using `evt.getNewBinding()`. Its old binding (before the rename) can be obtained using `evt.getOldBinding()`. One of these may be null if the old/new binding was outside the scope in which the listener has registered interest.

    Parameters:
      `evt` - The nonnull event.
    See Also:
      - `NamingEvent.OBJECT_RENAMED`