Java javax.swing Class JApplet（JDK8）

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Java™ Platform
Standard Ed. 8

All Classes

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Constr |
Method

Detail:
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Constr |
Method

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, the add, remove, and setLayout methods of this class are overridden, so that they delegate calls to the corresponding methods of the ContentPane. For example, you can add a child component to an applet as follows:
```
       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: Swing is not thread safe. For more information see Swing's Threading Policy.

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 JavaBeans™ has been added to the java.beans package. Please see XMLEncoder.
See Also:

RootPaneContainer

Nested Class Summary

Nested Classes
Modifier and Type	Class and Description
`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.BaselineResizeBehavior, Component.BltBufferStrategy, Component.FlipBufferStrategy

Field Summary

Fields
Modifier and Type	Field and Description
`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

Constructors
Constructor and Description
`JApplet()` Creates a swing applet instance.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`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.
`Graphics`	`getGraphics()` Creates a graphics context for this component.
`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.
`TransferHandler`	`getTransferHandler()` Gets the `transferHandler` property.
`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`	`repaint(long time, int x, int y, int width, int height)` Repaints the specified rectangle of this component within `time` milliseconds.
`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`	`setTransferHandler(TransferHandler newHandler)` Sets the `transferHandler` property, which is a mechanism to support transfer of data into this component.
`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, isValidateRoot, 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, 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, getBaseline, getBaselineResizeBehavior, getBounds, getBounds, getColorModel, getComponentListeners, getComponentOrientation, getCursor, getDropTarget, getFocusCycleRootAncestor, getFocusListeners, getFocusTraversalKeysEnabled, getFont, getFontMetrics, getForeground, 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, requestFocus, requestFocus, requestFocusInWindow, requestFocusInWindow, reshape, revalidate, 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, transferFocusBackward, 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.
  - setTransferHandler
```
public void setTransferHandler(TransferHandler newHandler)
```
    Sets the transferHandler property, which is a mechanism to support transfer of data into this component. Use null if the component does not support data transfer operations.
    If the system property suppressSwingDropSupport is false (the default) and the current drop target on this component is either null or not a user-set drop target, this method will change the drop target as follows: If newHandler is null it will clear the drop target. If not null it will install a new DropTarget.
    
    Note: When used with JApplet, TransferHandler only provides data import capability, as the data export related methods are currently typed to JComponent.
    
    Please see How to Use Drag and Drop and Data Transfer, a section in The Java Tutorial, for more information.
    
    Parameters:
    
    newHandler - the new TransferHandler
    
    Since:
    
    1.6
    
    See Also:
    
    TransferHandler, getTransferHandler(), Component.setDropTarget(java.awt.dnd.DropTarget)
  - getTransferHandler
```
public TransferHandler getTransferHandler()
```
    Gets the transferHandler property.
    
    Returns:
    
    the value of the transferHandler property
    
    Since:
    
    1.6
    
    See Also:
    
    TransferHandler, setTransferHandler(javax.swing.TransferHandler)
  - 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 forwarded; 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 forward 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)
  - getGraphics
```
public Graphics getGraphics()
```
    Creates a graphics context for this component. This method will return null if this component is currently not displayable.
    
    Overrides:
    
    getGraphics in class Component
    
    Returns:
    
    a graphics context for this component, or null if it has none
    
    Since:
    
    1.6
    
    See Also:
    
    Component.paint(java.awt.Graphics)
  - repaint
```
public void repaint(long time,
                    int x,
                    int y,
                    int width,
                    int height)
```
    Repaints the specified rectangle of this component within time milliseconds. Refer to RepaintManager for details on how the repaint is handled.
    
    Overrides:
    
    repaint in class Component
    
    Parameters:
    
    time - maximum time in milliseconds before update
    
    x - the x coordinate
    
    y - the y coordinate
    
    width - the width
    
    height - the height
    
    Since:
    
    1.6
    
    See Also:
    
    RepaintManager
  - 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

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Java™ Platform
Standard Ed. 8

All Classes

Summary:
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Field |
Constr |
Method

Detail:
Field |
Constr |
Method

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Java javax.swing Class JApplet（JDK8）

Class JApplet

Nested Class Summary

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

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

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

Nested classes/interfaces inherited from class java.awt.Component

Field Summary

Fields inherited from class java.awt.Component

Fields inherited from interface java.awt.image.ImageObserver

Constructor Summary

Method Summary

Methods inherited from class java.applet.Applet

Methods inherited from class java.awt.Panel

Methods inherited from class java.awt.Container

Methods inherited from class java.awt.Component

Methods inherited from class java.lang.Object

Field Detail

rootPane

rootPaneCheckingEnabled

accessibleContext

Constructor Detail

JApplet

Method Detail

createRootPane

setTransferHandler

getTransferHandler

update

setJMenuBar

getJMenuBar

isRootPaneCheckingEnabled

setRootPaneCheckingEnabled

addImpl

remove

setLayout

getRootPane

setRootPane

getContentPane

setContentPane

getLayeredPane

setLayeredPane

getGlassPane

setGlassPane

getGraphics

repaint

paramString

getAccessibleContext