Name: sdR10048 Date: 05/12/2001


Four methods of class java.awt.KeyboardFocusManager

public PropertyChangeListener[] getPropertyChangeListeners()
public PropertyChangeListener[] getPropertyChangeListeners(StringápropertyName)
public VetoableChangeListener[] getVetoableChangeListeners()
public VetoableChangeListener[] getVetoableChangeListeners(StringápropertyName)

throw NullPointerException in its first time calling. See example.
--------------------------------------------------
[archer] ~/tmp
% cat test.java
import java.awt.*;

public class test {
    public static void main(String[] args) {
        KeyboardFocusManager kfm =
            KeyboardFocusManager.getCurrentKeyboardFocusManager();
        try {
            kfm.getVetoableChangeListeners();
        } catch (Exception e) {
            e.printStackTrace();
        }
        try {
            kfm.getVetoableChangeListeners("");
        } catch (Exception e) {
            e.printStackTrace();
        }
        try {
            kfm.getPropertyChangeListeners();
        } catch (Exception e) {
            e.printStackTrace();
        }
        try {
            kfm.getPropertyChangeListeners("");
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

[archer] ~/tmp
% java -version
java version "1.4.0-beta"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.0-beta-b61)
Java HotSpot(TM) Client VM (build 1.4.0-beta-b61, mixed mode)

[archer] ~/tmp
% javac test.java

[archer] ~/tmp
% java test
java.lang.NullPointerException
        at java.awt.KeyboardFocusManager.getVetoableChangeListeners(KeyboardFocusManager.java:1281)
        at test.main(test.java:8)
java.lang.NullPointerException
        at java.awt.KeyboardFocusManager.getVetoableChangeListeners(KeyboardFocusManager.java:1355)
        at test.main(test.java:13)
java.lang.NullPointerException
        at java.awt.KeyboardFocusManager.getPropertyChangeListeners(KeyboardFocusManager.java:1112)
        at test.main(test.java:18)
java.lang.NullPointerException
        at java.awt.KeyboardFocusManager.getPropertyChangeListeners(KeyboardFocusManager.java:1195)
        at test.main(test.java:23)

--------------------------------------------------
Mr. Javadoc says:

public PropertyChangeListener[] getPropertyChangeListeners()

Returns an array of all the property change listeners registered
on this keyboard focus manager.
Returns:
all of this keyboard focus manager's PropertyChangeListeners
or an empty array if no property change listeners are currently registered
Since:
1.4
See:
  addPropertyChangeListener(java.beans.PropertyChangeListener),
  removePropertyChangeListener(java.beans.PropertyChangeListener),
  getPropertyChangeListeners(java.lang.String)


public PropertyChangeListener[] getPropertyChangeListeners(StringápropertyName)

Returns an array of all the PropertyChangeListeners associated with the named
property.
Returns:
all of the PropertyChangeListeners associated with the named property or
an empty array if no such listeners have been added.
Since:
1.4
See:
#addPropertyChangeListener(java.lang.String),
#removePropertyChangeListener(java.lang.String)

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