Package gnu.cajo.invoke
Class Client
java.lang.Object
java.awt.Component
java.awt.Container
java.awt.Panel
java.applet.Applet
gnu.cajo.invoke.Client
- All Implemented Interfaces:
ImageObserver
,MenuContainer
,Serializable
,Accessible
This class is used to create a hosting VM to receive a graphical proxy
object, from a remote VM. The client will require one outbound port, on
which to commuinicate with its proxy server and one on inbound, on which to
receive asynchronous callbacks from the server. It will also require one
short-term inbound port on which to receive the proxy class files. If the
client is behind a firewall, these will have to be open.
- Version:
- 1.0, 01-Nov-99 Initial release
- See Also:
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Nested Class Summary
Nested ClassesNested 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
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Field Summary
FieldsModifier and TypeFieldDescriptionprivate Graphics
private Image
private static Object
private static final long
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
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionvoid
destroy()
This method is called from the AppleContext, when the applet is being disposed.static Frame
This method is used by items to create a frame containing the AWT or Swing component.This method provides the standard mechanism to identify this applet.String[][]
When running as an applet, this method describes the optional client parameters.void
init()
When running as an applet, this method will connect back to its hosting server and request the item from the server's rmiregistry.static void
The application creates a graphical proxy hosting VM.void
start()
This method is called from the AppleContext, each time the applet becomes visible.void
stop()
This method is called from the AppleContext, each time the applet becomes invisible.void
The update method double buffers the applet's paint method, to reduce flicker from the default background repainting.Methods inherited from class java.applet.Applet
getAccessibleContext, getAppletContext, getAudioClip, getAudioClip, getCodeBase, getDocumentBase, getImage, getImage, getLocale, getParameter, isActive, isValidateRoot, newAudioClip, play, play, resize, resize, setStub, showStatus
Methods inherited from class java.awt.Container
add, add, add, add, add, addContainerListener, addImpl, 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, paramString, preferredSize, print, printComponents, processContainerEvent, processEvent, remove, remove, removeAll, removeContainerListener, removeNotify, setComponentZOrder, setFocusCycleRoot, setFocusTraversalKeys, setFocusTraversalPolicy, setFocusTraversalPolicyProvider, setFont, setLayout, 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, getGraphics, getGraphicsConfiguration, getHeight, getHierarchyBoundsListeners, getHierarchyListeners, getIgnoreRepaint, getInputContext, getInputMethodListeners, getInputMethodRequests, getKeyListeners, getLocation, getLocation, getLocationOnScreen, getMouseListeners, getMouseMotionListeners, getMousePosition, getMouseWheelListeners, getName, getParent, 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, requestFocus, requestFocus, requestFocusInWindow, requestFocusInWindow, requestFocusInWindow, reshape, revalidate, setBackground, setBounds, setBounds, setComponentOrientation, setCursor, setDropTarget, setEnabled, setFocusable, setFocusTraversalKeysEnabled, setForeground, setIgnoreRepaint, setLocale, setLocation, setLocation, setMaximumSize, setMinimumSize, setMixingCutoutShape, setName, setPreferredSize, setSize, setSize, setVisible, show, show, size, toString, transferFocus, transferFocusBackward, transferFocusUpCycle
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Field Details
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serialVersionUID
private static final long serialVersionUID- See Also:
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proxy
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gbuffer
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ibuffer
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Constructor Details
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Client
public Client()The default constructor does nothing. Initialization is done when the applet is loaded into the browser, or when it is instantiated as an application.
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Method Details
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getAppletInfo
This method provides the standard mechanism to identify this applet.- Overrides:
getAppletInfo
in classApplet
- Returns:
- The identification string for this applet.
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getParameterInfo
When running as an applet, this method describes the optional client parameters. There are five such parameters which can be specified:- The
proxyName
parameter is the name of the proxy server item registered in the server's rmiregistry. Unspecified it will be "main". - The
proxyPort
parameter is the outbound port number on which to contact the proxy server. Unspecified it will be 1099. If the client is operating behind a firewall, the must be a permitted outbound port. - The
clientHost
parameter is the external domain name or IP address the server must use to callback its proxy. It may need to be specified if the client is operating behind a NAT router. Unspecified it will be the client's default host address. - The
clientPort
parameter is the external inbound port number on which the server can contact its proxy. It may need to be specified if the client is behind NAT, to map to the correct local port. If a firewall is being used, it must be a permitted inbound port. Unspecified, it will be the same as the local port value below. - The
localPort
parameter is the internal inbound port number on which the server can contact its proxy. It may need to be specified if the client is behind NAT, to map to the correct remote port. Unspecified, it will be anonymous.
- Overrides:
getParameterInfo
in classApplet
- Returns:
- The parameter / information array.
- The
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init
public void init()When running as an applet, this method will connect back to its hosting server and request the item from the server's rmiregistry. Next it will invoke a getProxy(null) on the remote reference to request its proxy item. If the item returns the proxy in a MarshalledObject, it will be extracted automatically. If the returned object is a proxy, the client will invoke its init method, passing it a remote reference itself, and to obtain its primary graphical representation, which will then be added into the applet's panel. The proxy can pass its remote reference back to its hosting item, or to other remote items, on which they can asynchronously call it back. -
start
public void start()This method is called from the AppleContext, each time the applet becomes visible. It will attempt to invoke a no-arg start method on the proxy, in the event that it supports one. Support of the method by the proxy is optional. -
stop
public void stop()This method is called from the AppleContext, each time the applet becomes invisible. It will attempt to invoke a no-arg stot method on the proxy, in the event that it supports one. Support of the method by the proxy is optional. -
destroy
public void destroy()This method is called from the AppleContext, when the applet is being disposed. It will attempt to invoke a no-arg destroy method on the proxy, in the event that it supports one. Support of the method by the proxy is optional. -
update
The update method double buffers the applet's paint method, to reduce flicker from the default background repainting. -
frame
This method is used by items to create a frame containing the AWT or Swing component. If the component implements WindowListener, it will be added to its display frame, before being made visible. For AWT components, the frame will be automatically double buffered, for JComponents.- Parameters:
component
- The AWT/Swing component, typically returned from a proxy initialization, to be framed.- Returns:
- the AWT Frame or Swing JFrame containing the component, already visible.
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main
The application creates a graphical proxy hosting VM. With the URL argument provided, it will use the staticgetItem
method of theRemote
class to contact the server. It will then invoke a null-argument getProxy on the resulting reference to request the primary proxy object of the item. If the proxy is a Swing JComponent, it will be displayed in a JFrame. If it is an AWT Component, it will be displayed in a Frame.
When using Client from the command line, it is possible to set the Client frame explicitly. To do this, simply type:
java -cp cajo.jar -Dgnu.cajo.invoke.Client.title="My Frame Title" gnu.cajo.invoke.Client //myHost:1198/test
Note: When running as an application (except via WebStart) it will load a NoSecurityManager, therefore, if no external SecurityManager is specified in the startup command line; the arriving proxies will have full permissions on this machine!
To restrict client proxies permissions, use a startup invocation similar to the following:
java -cp cajo.jar -Djava.security.manager -Djava.security.policy=client.policy ... gnu.cajo.invoke.Client ...
See the project client documentation, for more details.
The startup can take up to five additional optional configuration parameters, in this order:- args[0] - The URL where to get the graphical proxy item:
file:// http:// ftp:// ..., //host:port/name (rmiregistry), /path/name (serialized), or path/name (class).
If unspecified, a graphical loader utility will be launched. - args[1] - The optional external client port number, if using NAT.
- args[2] - The optional external client host name, if using NAT.
- args[3] - The optional internal client port number, if using NAT.
- args[4] - The optional internal client host name, if multi home/NIC.
- Throws:
Exception
- args[0] - The URL where to get the graphical proxy item:
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