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## javax.swing
Class JApplet

    java.lang.Object
      java.awt.Component
          java.awt.Container
              java.awt.Panel
                  java.applet.Applet
                      javax.swing.JApplet

All Implemented Interfaces:
  ImageObserver, MenuContainer, Serializable, Accessible, RootPaneContainer

    public class JApplet

extends Applet
implements Accessible, RootPaneContainer

An extended version of `java.applet.Applet` that adds support for the JFC/Swing component architecture. You can find task-oriented documentation about using `JApplet` in The Java Tutorial, in the section How to Make Applets.

The `JApplet` class is slightly incompatible with `java.applet.Applet`. `JApplet` contains a `JRootPane` as its only child. The `contentPane` should be the parent of any children of the `JApplet`. As a convenience `add` and its variants, `remove` and `setLayout` have been overridden to forward to the `contentPane` as necessary. This means you can write:

           applet.add(child);

And the child will be added to the `contentPane`. The `contentPane` will always be non-`null`. Attempting to set it to `null` will cause the `JApplet` to throw an exception. The default `contentPane` will have a `BorderLayout` manager set on it. Refer to `RootPaneContainer` for details on adding, removing and setting the `LayoutManager` of a `JApplet`.

Please see the `JRootPane` documentation for a complete description of the `contentPane`, `glassPane`, and `layeredPane` properties.

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`.

See Also:
  `RootPaneContainer`

Nested Class Summary
`protected class` | `JApplet.AccessibleJApplet` This class implements accessibility support for the `JApplet` class.

Nested classes/interfaces inherited from class java.applet.Applet
`Applet.AccessibleApplet`

Nested classes/interfaces inherited from class java.awt.Panel
`Panel.AccessibleAWTPanel`

Nested classes/interfaces inherited from class java.awt.Container
`Container.AccessibleAWTContainer`

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

Field Summary
`protected AccessibleContext` | `accessibleContext`
`protected JRootPane` | `rootPane`
`protected boolean` | `rootPaneCheckingEnabled` If true then calls to `add` and `setLayout` will be forwarded to the `contentPane`.

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

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

Constructor Summary
`JApplet()` Creates a swing applet instance.

Method Summary
`protected void` | `addImpl(Component comp, Object constraints, int index)` Adds the specified child `Component`.
`protected JRootPane` | `createRootPane()` Called by the constructor methods to create the default rootPane.
`AccessibleContext` | `getAccessibleContext()` Gets the AccessibleContext associated with this JApplet.
`Container` | `getContentPane()` Returns the contentPane object for this applet.
`Component` | `getGlassPane()` Returns the glassPane object for this applet.
`JMenuBar` | `getJMenuBar()` Returns the menubar set on this applet.
`JLayeredPane` | `getLayeredPane()` Returns the layeredPane object for this applet.
`JRootPane` | `getRootPane()` Returns the rootPane object for this applet.
`protected boolean` | `isRootPaneCheckingEnabled()` Returns whether calls to `add` and `setLayout` are forwarded to the `contentPane`.
`protected String` | `paramString()` Returns a string representation of this JApplet.
`void` | `remove(Component comp)` Removes the specified component from the container.
`void` | `setContentPane(Container contentPane)` Sets the contentPane property.
`void` | `setGlassPane(Component glassPane)` Sets the glassPane property.
`void` | `setJMenuBar(JMenuBar menuBar)` Sets the menubar for this applet.
`void` | `setLayeredPane(JLayeredPane layeredPane)` Sets the layeredPane property.
`void` | `setLayout(LayoutManager manager)` Sets the `LayoutManager`.
`protected void` | `setRootPane(JRootPane root)` Sets the rootPane property.
`protected void` | `setRootPaneCheckingEnabled(boolean enabled)` Sets whether calls to `add` and `setLayout` are forwarded to the `contentPane`.
`void` | `update(Graphics g)` Just calls `paint(g)`.

Methods inherited from class java.applet.Applet
`destroy, getAppletContext, getAppletInfo, getAudioClip, getAudioClip, getCodeBase, getDocumentBase, getImage, getImage, getLocale, getParameter, getParameterInfo, init, isActive, newAudioClip, play, play, resize, resize, setStub, showStatus, start, stop`

Methods inherited from class java.awt.Panel
`addNotify`

Methods inherited from class java.awt.Container
`add, add, add, add, add, addContainerListener, addPropertyChangeListener, addPropertyChangeListener, applyComponentOrientation, areFocusTraversalKeysSet, countComponents, deliverEvent, doLayout, findComponentAt, findComponentAt, getAlignmentX, getAlignmentY, getComponent, getComponentAt, getComponentAt, getComponentCount, getComponents, getComponentZOrder, getContainerListeners, getFocusTraversalKeys, getFocusTraversalPolicy, getInsets, getLayout, getListeners, getMaximumSize, getMinimumSize, getMousePosition, getPreferredSize, insets, invalidate, isAncestorOf, isFocusCycleRoot, isFocusCycleRoot, isFocusTraversalPolicyProvider, isFocusTraversalPolicySet, layout, list, list, locate, minimumSize, paint, paintComponents, preferredSize, print, printComponents, processContainerEvent, processEvent, remove, removeAll, removeContainerListener, removeNotify, setComponentZOrder, setFocusCycleRoot, setFocusTraversalKeys, setFocusTraversalPolicy, setFocusTraversalPolicyProvider, setFont, 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, contains, createImage, createImage, createVolatileImage, createVolatileImage, disable, disableEvents, dispatchEvent, enable, enable, enableEvents, enableInputMethods, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, getBackground, getBounds, getBounds, getColorModel, getComponentListeners, getComponentOrientation, getCursor, getDropTarget, getFocusCycleRootAncestor, getFocusListeners, getFocusTraversalKeysEnabled, getFont, getFontMetrics, getForeground, getGraphics, getGraphicsConfiguration, getHeight, getHierarchyBoundsListeners, getHierarchyListeners, getIgnoreRepaint, getInputContext, getInputMethodListeners, getInputMethodRequests, getKeyListeners, getLocation, getLocation, getLocationOnScreen, getMouseListeners, getMouseMotionListeners, getMousePosition, getMouseWheelListeners, getName, getParent, getPeer, getPropertyChangeListeners, getPropertyChangeListeners, getSize, getSize, getToolkit, getTreeLock, getWidth, getX, getY, gotFocus, handleEvent, hasFocus, hide, imageUpdate, inside, isBackgroundSet, isCursorSet, isDisplayable, isDoubleBuffered, isEnabled, isFocusable, isFocusOwner, isFocusTraversable, isFontSet, isForegroundSet, isLightweight, isMaximumSizeSet, isMinimumSizeSet, isOpaque, isPreferredSizeSet, isShowing, isValid, isVisible, keyDown, keyUp, list, list, list, location, lostFocus, mouseDown, mouseDrag, mouseEnter, mouseExit, mouseMove, mouseUp, move, nextFocus, paintAll, postEvent, prepareImage, prepareImage, printAll, processComponentEvent, processFocusEvent, processHierarchyBoundsEvent, processHierarchyEvent, processInputMethodEvent, processKeyEvent, processMouseEvent, processMouseMotionEvent, processMouseWheelEvent, remove, removeComponentListener, removeFocusListener, removeHierarchyBoundsListener, removeHierarchyListener, removeInputMethodListener, removeKeyListener, removeMouseListener, removeMouseMotionListener, removeMouseWheelListener, removePropertyChangeListener, removePropertyChangeListener, repaint, repaint, repaint, repaint, requestFocus, requestFocus, requestFocusInWindow, requestFocusInWindow, reshape, setBackground, setBounds, setBounds, setComponentOrientation, setCursor, setDropTarget, setEnabled, setFocusable, setFocusTraversalKeysEnabled, setForeground, setIgnoreRepaint, setLocale, setLocation, setLocation, setMaximumSize, setMinimumSize, setName, setPreferredSize, setSize, setSize, setVisible, show, show, size, toString, transferFocus, transferFocusUpCycle`

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

Field Detail

### rootPane

    protected JRootPane rootPane

See Also:
  `getRootPane()`, `setRootPane(javax.swing.JRootPane)`

### rootPaneCheckingEnabled

    protected boolean rootPaneCheckingEnabled

  If true then calls to `add` and `setLayout` will be forwarded to the `contentPane`. This is initially false, but is set to true when the `JApplet` is constructed.

  See Also:
    `isRootPaneCheckingEnabled()`, `setRootPaneCheckingEnabled(boolean)`, `RootPaneContainer`

### accessibleContext

    protected AccessibleContext accessibleContext

Constructor Detail

### JApplet

    public JApplet()
            throws HeadlessException

  Creates a swing applet instance.

  This constructor sets the component's locale property to the value returned by `JComponent.getDefaultLocale`.

  Throws:
    `HeadlessException` - if GraphicsEnvironment.isHeadless() returns true.
  See Also:
    `GraphicsEnvironment.isHeadless()`, `JComponent.getDefaultLocale()`

Method Detail

### createRootPane

    protected JRootPane createRootPane()

  Called by the constructor methods to create the default rootPane.

### update

    public void update(Graphics g)

  Just calls `paint(g)`. This method was overridden to prevent an unnecessary call to clear the background.

  Overrides:
    `update` in class `Container`
  Parameters:
    `g` - the specified Graphics window
  See Also:
    `Component.update(Graphics)`

### setJMenuBar

    public void setJMenuBar(JMenuBar menuBar)

  Sets the menubar for this applet.

  Parameters:
    `menuBar` - the menubar being placed in the applet
  See Also:
    `getJMenuBar()`

### getJMenuBar

    public JMenuBar getJMenuBar()

  Returns the menubar set on this applet.

  See Also:
    `setJMenuBar(javax.swing.JMenuBar)`

### isRootPaneCheckingEnabled

    protected boolean isRootPaneCheckingEnabled()

  Returns whether calls to `add` and `setLayout` are forwarded to the `contentPane`.

  Returns:
    true if `add` and `setLayout` are fowarded; false otherwise
  See Also:
    `addImpl(java.awt.Component, java.lang.Object, int)`, `setLayout(java.awt.LayoutManager)`, `setRootPaneCheckingEnabled(boolean)`, `RootPaneContainer`

### setRootPaneCheckingEnabled

    protected void setRootPaneCheckingEnabled(boolean enabled)

  Sets whether calls to `add` and `setLayout` are forwarded to the `contentPane`.

  Parameters:
    `enabled` - true if `add` and `setLayout` are forwarded, false if they should operate directly on the `JApplet`.
  See Also:
    `addImpl(java.awt.Component, java.lang.Object, int)`, `setLayout(java.awt.LayoutManager)`, `isRootPaneCheckingEnabled()`, `RootPaneContainer`

### addImpl

    protected void addImpl(Component comp,
                           Object constraints,
                           int index)

  Adds the specified child `Component`. This method is overridden to conditionally forwad calls to the `contentPane`. By default, children are added to the `contentPane` instead of the frame, refer to `RootPaneContainer` for details.

  Overrides:
    `addImpl` in class `Container`
  Parameters:
    `comp` - the component to be enhanced
    `constraints` - the constraints to be respected
    `index` - the index
  Throws:
    `IllegalArgumentException` - if `index` is invalid
    `IllegalArgumentException` - if adding the container's parent to itself
    `IllegalArgumentException` - if adding a window to a container
  See Also:
    `setRootPaneCheckingEnabled(boolean)`, `RootPaneContainer`

### remove

    public void remove(Component comp)

  Removes the specified component from the container. If `comp` is not the `rootPane`, this will forward the call to the `contentPane`. This will do nothing if `comp` is not a child of the `JFrame` or `contentPane`.

  Overrides:
    `remove` in class `Container`
  Parameters:
    `comp` - the component to be removed
  Throws:
    `NullPointerException` - if `comp` is null
  See Also:
    `Container.add(java.awt.Component)`, `RootPaneContainer`

### setLayout

    public void setLayout(LayoutManager manager)

  Sets the `LayoutManager`. Overridden to conditionally forward the call to the `contentPane`. Refer to `RootPaneContainer` for more information.

  Overrides:
    `setLayout` in class `Container`
  Parameters:
    `manager` - the `LayoutManager`
  See Also:
    `setRootPaneCheckingEnabled(boolean)`, `RootPaneContainer`

### getRootPane

    public JRootPane getRootPane()

  Returns the rootPane object for this applet.

  Specified by:
    `getRootPane` in interface `RootPaneContainer`
  Returns:
    this components single JRootPane child.
  See Also:
    `setRootPane(javax.swing.JRootPane)`, `RootPaneContainer.getRootPane()`

### setRootPane

    protected void setRootPane(JRootPane root)

  Sets the rootPane property. This method is called by the constructor.

  Parameters:
    `root` - the rootPane object for this applet
  See Also:
    `getRootPane()`

### getContentPane

    public Container getContentPane()

  Returns the contentPane object for this applet.

  Specified by:
    `getContentPane` in interface `RootPaneContainer`
  Returns:
    the value of the contentPane property.
  See Also:
    `setContentPane(java.awt.Container)`, `RootPaneContainer.getContentPane()`

### setContentPane

    public void setContentPane(Container contentPane)

  Sets the contentPane property. This method is called by the constructor.

  Specified by:
    `setContentPane` in interface `RootPaneContainer`
  Parameters:
    `contentPane` - the contentPane object for this applet
  Throws:
    `IllegalComponentStateException` - (a runtime exception) if the content pane parameter is null
  See Also:
    `getContentPane()`, `RootPaneContainer.setContentPane(java.awt.Container)`

### getLayeredPane

    public JLayeredPane getLayeredPane()

  Returns the layeredPane object for this applet.

  Specified by:
    `getLayeredPane` in interface `RootPaneContainer`
  Returns:
    the value of the layeredPane property.
  Throws:
    `IllegalComponentStateException` - (a runtime exception) if the layered pane parameter is null
  See Also:
    `setLayeredPane(javax.swing.JLayeredPane)`, `RootPaneContainer.getLayeredPane()`

### setLayeredPane

    public void setLayeredPane(JLayeredPane layeredPane)

  Sets the layeredPane property. This method is called by the constructor.

  Specified by:
    `setLayeredPane` in interface `RootPaneContainer`
  Parameters:
    `layeredPane` - the layeredPane object for this applet
  See Also:
    `getLayeredPane()`, `RootPaneContainer.setLayeredPane(javax.swing.JLayeredPane)`

### getGlassPane

    public Component getGlassPane()

  Returns the glassPane object for this applet.

  Specified by:
    `getGlassPane` in interface `RootPaneContainer`
  Returns:
    the value of the glassPane property.
  See Also:
    `setGlassPane(java.awt.Component)`, `RootPaneContainer.getGlassPane()`

### setGlassPane

    public void setGlassPane(Component glassPane)

  Sets the glassPane property. This method is called by the constructor.

  Specified by:
    `setGlassPane` in interface `RootPaneContainer`
  Parameters:
    `glassPane` - the glassPane object for this applet
  See Also:
    `getGlassPane()`, `RootPaneContainer.setGlassPane(java.awt.Component)`

### paramString

    protected String paramString()

  Returns a string representation of this JApplet. 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 `Container`
  Returns:
    a string representation of this JApplet.

### getAccessibleContext

    public AccessibleContext getAccessibleContext()

  Gets the AccessibleContext associated with this JApplet. For JApplets, the AccessibleContext takes the form of an AccessibleJApplet. A new AccessibleJApplet instance is created if necessary.

  Specified by:
    `getAccessibleContext` in interface `Accessible`
  Overrides:
    `getAccessibleContext` in class `Applet`
  Returns:
    an AccessibleJApplet that serves as the AccessibleContext of this JApplet

Overview | Package | Class | Use | Tree | Deprecated | Index | Help
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For further API reference and developer documentation, see Java 2 SDK SE Developer Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.

Copyright 2004 Sun Microsystems, Inc. All rights reserved. Use is subject to license terms. Also see the documentation redistribution policy.