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## javax.swing
Class JButton

    java.lang.Object
      |
      +--java.awt.Component
            |
            +--java.awt.Container
                  |
                  +--javax.swing.JComponent
                        |
                        +--javax.swing.AbstractButton
                              |
                              +--javax.swing.JButton

All Implemented Interfaces:
  Accessible, ImageObserver, ItemSelectable, MenuContainer, Serializable, SwingConstants

Direct Known Subclasses:
  BasicArrowButton, MetalComboBoxButton

public class JButton
extends AbstractButton
implements Accessible

An implementation of a "push" button. See How to Use Buttons, Check Boxes, and Radio Buttons in The Java Tutorial for information and examples of using buttons.

For the keyboard keys used by this component in the standard Look and Feel (L&F) renditions, see the `JButton` key assignments.

Warning: Serialized objects of this class will not be compatible with future Swing releases. The current serialization support is appropriate for short term storage or RMI between applications running the same version of Swing. As of 1.4, support for long term storage of all JavaBeansTM has been added to the `java.beans` package. Please see `XMLEncoder`.

Nested Class Summary
`protected class` | `JButton.AccessibleJButton` This class implements accessibility support for the `JButton` class.

Nested classes inherited from class javax.swing.AbstractButton
`AbstractButton.ButtonChangeListener`

Nested classes inherited from class javax.swing.JComponent
``

Nested classes inherited from class java.awt.Container
``

Nested classes inherited from class java.awt.Component
`Component.BltBufferStrategy, Component.FlipBufferStrategy`

Field Summary

Fields inherited from class javax.swing.AbstractButton
`actionListener, BORDER_PAINTED_CHANGED_PROPERTY, changeEvent, changeListener, CONTENT_AREA_FILLED_CHANGED_PROPERTY, DISABLED_ICON_CHANGED_PROPERTY, DISABLED_SELECTED_ICON_CHANGED_PROPERTY, FOCUS_PAINTED_CHANGED_PROPERTY, HORIZONTAL_ALIGNMENT_CHANGED_PROPERTY, HORIZONTAL_TEXT_POSITION_CHANGED_PROPERTY, ICON_CHANGED_PROPERTY, itemListener, MARGIN_CHANGED_PROPERTY, MNEMONIC_CHANGED_PROPERTY, model, MODEL_CHANGED_PROPERTY, PRESSED_ICON_CHANGED_PROPERTY, ROLLOVER_ENABLED_CHANGED_PROPERTY, ROLLOVER_ICON_CHANGED_PROPERTY, ROLLOVER_SELECTED_ICON_CHANGED_PROPERTY, SELECTED_ICON_CHANGED_PROPERTY, TEXT_CHANGED_PROPERTY, VERTICAL_ALIGNMENT_CHANGED_PROPERTY, VERTICAL_TEXT_POSITION_CHANGED_PROPERTY`

Fields inherited from class javax.swing.JComponent
`accessibleContext, listenerList, TOOL_TIP_TEXT_KEY, ui, UNDEFINED_CONDITION, WHEN_ANCESTOR_OF_FOCUSED_COMPONENT, WHEN_FOCUSED, WHEN_IN_FOCUSED_WINDOW`

Fields inherited from class java.awt.Component
`BOTTOM_ALIGNMENT, CENTER_ALIGNMENT, LEFT_ALIGNMENT, RIGHT_ALIGNMENT, TOP_ALIGNMENT`

Fields inherited from interface javax.swing.SwingConstants
`BOTTOM, CENTER, EAST, HORIZONTAL, LEADING, LEFT, NEXT, NORTH, NORTH_EAST, NORTH_WEST, PREVIOUS, RIGHT, SOUTH, SOUTH_EAST, SOUTH_WEST, TOP, TRAILING, VERTICAL, WEST`

Fields inherited from interface java.awt.image.ImageObserver
`ABORT, ALLBITS, ERROR, FRAMEBITS, HEIGHT, PROPERTIES, SOMEBITS, WIDTH`

Constructor Summary
`JButton()` Creates a button with no set text or icon.
`JButton(Action a)` Creates a button where properties are taken from the `Action` supplied.
`JButton(Icon icon)` Creates a button with an icon.
`JButton(String text)` Creates a button with text.
`JButton(String text, Icon icon)` Creates a button with initial text and an icon.

Method Summary
`protected void` | `configurePropertiesFromAction(Action a)` Factory method which sets the `AbstractButton`'s properties according to values from the `Action` instance.
`AccessibleContext` | `getAccessibleContext()` Gets the `AccessibleContext` associated with this `JButton`.
`String` | `getUIClassID()` Returns a string that specifies the name of the L&F class that renders this component.
`boolean` | `isDefaultButton()` Gets the value of the `defaultButton` property, which if `true` means that this button is the current default button for its `JRootPane`.
`boolean` | `isDefaultCapable()` Gets the value of the `defaultCapable` property.
`protected String` | `paramString()` Returns a string representation of this `JButton`.
`void` | `removeNotify()` Overrides `JComponent.removeNotify` to check if this button is currently set as the default button on the `RootPane`, and if so, sets the `RootPane`'s default button to `null` to ensure the `RootPane` doesn't hold onto an invalid button reference.
`void` | `setDefaultCapable(boolean defaultCapable)` Sets the `defaultCapable` property, which determines whether this button can be made the default button for its root pane.
`void` | `updateUI()` Resets the UI property to a value from the current look and feel.

Methods inherited from class javax.swing.AbstractButton
`addActionListener, addChangeListener, addItemListener, checkHorizontalKey, checkVerticalKey, createActionListener, createActionPropertyChangeListener, createChangeListener, createItemListener, doClick, doClick, fireActionPerformed, fireItemStateChanged, fireStateChanged, getAction, getActionCommand, getActionListeners, getChangeListeners, getDisabledIcon, getDisabledSelectedIcon, getDisplayedMnemonicIndex, getHorizontalAlignment, getHorizontalTextPosition, getIcon, getIconTextGap, getItemListeners, getLabel, getMargin, getMnemonic, getModel, getMultiClickThreshhold, getPressedIcon, getRolloverIcon, getRolloverSelectedIcon, getSelectedIcon, getSelectedObjects, getText, getUI, getVerticalAlignment, getVerticalTextPosition, imageUpdate, init, isBorderPainted, isContentAreaFilled, isFocusPainted, isRolloverEnabled, isSelected, paintBorder, removeActionListener, removeChangeListener, removeItemListener, setAction, setActionCommand, setBorderPainted, setContentAreaFilled, setDisabledIcon, setDisabledSelectedIcon, setDisplayedMnemonicIndex, setEnabled, setFocusPainted, setHorizontalAlignment, setHorizontalTextPosition, setIcon, setIconTextGap, setLabel, setMargin, setMnemonic, setMnemonic, setModel, setMultiClickThreshhold, setPressedIcon, setRolloverEnabled, setRolloverIcon, setRolloverSelectedIcon, setSelected, setSelectedIcon, setText, setUI, setVerticalAlignment, setVerticalTextPosition`

Methods inherited from class javax.swing.JComponent
`addAncestorListener, addNotify, addPropertyChangeListener, addPropertyChangeListener, addVetoableChangeListener, computeVisibleRect, contains, createToolTip, disable, enable, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, fireVetoableChange, getActionForKeyStroke, getActionMap, getAlignmentX, getAlignmentY, getAncestorListeners, getAutoscrolls, getBorder, getBounds, getClientProperty, getComponentGraphics, getConditionForKeyStroke, getDebugGraphicsOptions, getDefaultLocale, getGraphics, getHeight, getInputMap, getInputMap, getInputVerifier, getInsets, getInsets, getListeners, getLocation, getMaximumSize, getMinimumSize, getNextFocusableComponent, getPreferredSize, getPropertyChangeListeners, getPropertyChangeListeners, getRegisteredKeyStrokes, getRootPane, getSize, getToolTipLocation, getToolTipText, getToolTipText, getTopLevelAncestor, getTransferHandler, getVerifyInputWhenFocusTarget, getVetoableChangeListeners, getVisibleRect, getWidth, getX, getY, grabFocus, isDoubleBuffered, isLightweightComponent, isManagingFocus, isMaximumSizeSet, isMinimumSizeSet, isOpaque, isOptimizedDrawingEnabled, isPaintingTile, isPreferredSizeSet, isRequestFocusEnabled, isValidateRoot, paint, paintChildren, paintComponent, paintImmediately, paintImmediately, print, printAll, printBorder, printChildren, printComponent, processComponentKeyEvent, processKeyBinding, processKeyEvent, processMouseMotionEvent, putClientProperty, registerKeyboardAction, registerKeyboardAction, removeAncestorListener, removePropertyChangeListener, removePropertyChangeListener, removeVetoableChangeListener, repaint, repaint, requestDefaultFocus, requestFocus, requestFocus, requestFocusInWindow, requestFocusInWindow, resetKeyboardActions, reshape, revalidate, scrollRectToVisible, setActionMap, setAlignmentX, setAlignmentY, setAutoscrolls, setBackground, setBorder, setDebugGraphicsOptions, setDefaultLocale, setDoubleBuffered, setFont, setForeground, setInputMap, setInputVerifier, setMaximumSize, setMinimumSize, setNextFocusableComponent, setOpaque, setPreferredSize, setRequestFocusEnabled, setToolTipText, setTransferHandler, setUI, setVerifyInputWhenFocusTarget, setVisible, unregisterKeyboardAction, update`

Methods inherited from class java.awt.Container
`add, add, add, add, add, addContainerListener, addImpl, applyComponentOrientation, areFocusTraversalKeysSet, countComponents, deliverEvent, doLayout, findComponentAt, findComponentAt, getComponent, getComponentAt, getComponentAt, getComponentCount, getComponents, getContainerListeners, getFocusTraversalKeys, getFocusTraversalPolicy, getLayout, insets, invalidate, isAncestorOf, isFocusCycleRoot, isFocusCycleRoot, isFocusTraversalPolicySet, layout, list, list, locate, minimumSize, paintComponents, preferredSize, printComponents, processContainerEvent, processEvent, remove, remove, removeAll, removeContainerListener, setFocusCycleRoot, setFocusTraversalKeys, setFocusTraversalPolicy, setLayout, transferFocusBackward, transferFocusDownCycle, validate, validateTree`

Methods inherited from class java.awt.Component
`action, add, addComponentListener, addFocusListener, addHierarchyBoundsListener, addHierarchyListener, addInputMethodListener, addKeyListener, addMouseListener, addMouseMotionListener, addMouseWheelListener, bounds, checkImage, checkImage, coalesceEvents, contains, createImage, createImage, createVolatileImage, createVolatileImage, disableEvents, dispatchEvent, enable, enableEvents, enableInputMethods, getBackground, getBounds, getColorModel, getComponentListeners, getComponentOrientation, getCursor, getDropTarget, getFocusCycleRootAncestor, getFocusListeners, getFocusTraversalKeysEnabled, getFont, getFontMetrics, getForeground, getGraphicsConfiguration, getHierarchyBoundsListeners, getHierarchyListeners, getIgnoreRepaint, getInputContext, getInputMethodListeners, getInputMethodRequests, getKeyListeners, getLocale, getLocation, getLocationOnScreen, getMouseListeners, getMouseMotionListeners, getMouseWheelListeners, getName, getParent, getPeer, getSize, getToolkit, getTreeLock, gotFocus, handleEvent, hasFocus, hide, inside, isBackgroundSet, isCursorSet, isDisplayable, isEnabled, isFocusable, isFocusOwner, isFocusTraversable, isFontSet, isForegroundSet, isLightweight, isShowing, isValid, isVisible, keyDown, keyUp, list, list, list, location, lostFocus, mouseDown, mouseDrag, mouseEnter, mouseExit, mouseMove, mouseUp, move, nextFocus, paintAll, postEvent, prepareImage, prepareImage, processComponentEvent, processFocusEvent, processHierarchyBoundsEvent, processHierarchyEvent, processInputMethodEvent, processMouseEvent, processMouseWheelEvent, remove, removeComponentListener, removeFocusListener, removeHierarchyBoundsListener, removeHierarchyListener, removeInputMethodListener, removeKeyListener, removeMouseListener, removeMouseMotionListener, removeMouseWheelListener, repaint, repaint, repaint, resize, resize, setBounds, setBounds, setComponentOrientation, setCursor, setDropTarget, setFocusable, setFocusTraversalKeysEnabled, setIgnoreRepaint, setLocale, setLocation, setLocation, setName, setSize, setSize, show, show, size, toString, transferFocus, transferFocusUpCycle`

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

Constructor Detail

### JButton

    public JButton()

  Creates a button with no set text or icon.

### JButton

    public JButton(Icon icon)

  Creates a button with an icon.

Parameters:
  `icon` - the Icon image to display on the button

### JButton

    public JButton(String text)

  Creates a button with text.

Parameters:
  `text` - the text of the button

### JButton

    public JButton(Action a)

  Creates a button where properties are taken from the `Action` supplied.

Parameters:
  `a` - the `Action` used to specify the new button
Since:
  1.3

### JButton

    public JButton(String text,
                   Icon icon)

  Creates a button with initial text and an icon.

Parameters:
  `text` - the text of the button
  `icon` - the Icon image to display on the button

Method Detail

### updateUI

    public void updateUI()

  Resets the UI property to a value from the current look and feel.

  Overrides:
    `updateUI` in class `AbstractButton`
  See Also:
    `JComponent.updateUI()`

### getUIClassID

    public String getUIClassID()

  Returns a string that specifies the name of the L&F class that renders this component.

  Overrides:
    `getUIClassID` in class `JComponent`
  Returns:
    the string "ButtonUI"
  See Also:
    `JComponent.getUIClassID()`, `UIDefaults.getUI(javax.swing.JComponent)`

### isDefaultButton

    public boolean isDefaultButton()

  Gets the value of the `defaultButton` property, which if `true` means that this button is the current default button for its `JRootPane`. Most look and feels render the default button differently, and may potentially provide bindings to access the default button.

  Returns:
    the value of the `defaultButton` property
  See Also:
    `JRootPane.setDefaultButton(javax.swing.JButton)`, `isDefaultCapable()`

### isDefaultCapable

    public boolean isDefaultCapable()

  Gets the value of the `defaultCapable` property.

  Returns:
    the value of the `defaultCapable` property
  See Also:
    `setDefaultCapable(boolean)`, `isDefaultButton()`, `JRootPane.setDefaultButton(javax.swing.JButton)`

### setDefaultCapable

    public void setDefaultCapable(boolean defaultCapable)

  Sets the `defaultCapable` property, which determines whether this button can be made the default button for its root pane. The default value of the `defaultCapable` property is `true` unless otherwise specified by the look and feel.

  Parameters:
    `defaultCapable` - `true` if this button will be capable of being the default button on the `RootPane`; otherwise `false`
  See Also:
    `isDefaultCapable()`

### removeNotify

    public void removeNotify()

  Overrides `JComponent.removeNotify` to check if this button is currently set as the default button on the `RootPane`, and if so, sets the `RootPane`'s default button to `null` to ensure the `RootPane` doesn't hold onto an invalid button reference.

  Overrides:
    `removeNotify` in class `JComponent`
  See Also:
    `JComponent.registerKeyboardAction(java.awt.event.ActionListener, java.lang.String, javax.swing.KeyStroke, int)`

### configurePropertiesFromAction

    protected void configurePropertiesFromAction(Action a)

  Factory method which sets the `AbstractButton`'s properties according to values from the `Action` instance. The properties which get set may differ for `AbstractButton` subclasses. By default, the properties which get set are `Text, Icon, Enabled, ToolTipText, ActionCommand`, and `Mnemonic`.

  Overrides:
    `configurePropertiesFromAction` in class `AbstractButton`
  Parameters:
    `a` - the `Action` from which to get the properties, or `null`
  Since:
    1.3
See Also:
  `Action`, `AbstractButton.setAction(javax.swing.Action)`

### paramString

    protected String paramString()

  Returns a string representation of this `JButton`. This method is intended to be used only for debugging purposes, and the content and format of the returned string may vary between implementations. The returned string may be empty but may not be `null`.

  Overrides:
    `paramString` in class `AbstractButton`
  Returns:
    a string representation of this `JButton`

### getAccessibleContext

    public AccessibleContext getAccessibleContext()

  Gets the `AccessibleContext` associated with this `JButton`. For `JButton`s, the `AccessibleContext` takes the form of an `AccessibleJButton`. A new `AccessibleJButton` instance is created if necessary.

  Specified by:
    `getAccessibleContext` in interface `Accessible`
  Overrides:
    `getAccessibleContext` in class `JComponent`
  Returns:
    an `AccessibleJButton` that serves as the `AccessibleContext` of this `JButton`

Overview | Package | Class | Use | Tree | Deprecated | Index | Help
| JavaTM 2 Platform Std. Ed. v1.4.0
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