OpenJDK 1.22 · com.sun.tools.jconsole.JConsolePlugin

A JConsole plugin class. JConsole uses the service provider mechanism to search the JConsole plugins. Users can provide their JConsole plugins in a jar file containing a file named

META-INF/services/com.sun.tools.jconsole.JConsolePlugin

This file contains one line for each plugin, for example,

com.sun.example.JTop

which is the fully qualified class name of the class implementing JConsolePlugin.

To load the JConsole plugins in JConsole, run:

jconsole -pluginpath <plugin-path>

where <plugin-path> specifies the paths of JConsole plugins to look up which can be a directory or a jar file. Multiple paths are separated by the path separator character of the platform.

When a new JConsole window is created for a connection, an instance of each JConsolePlugin will be created. The JConsoleContext object is not available at its construction time. JConsole will set the JConsoleContext object for a plugin after the plugin object is created. It will then call its getTabs method and add the returned tabs to the JConsole window.

Modifier and Type	Field and Description
private volatile JConsoleContext	context
private List<PropertyChangeListener>	listeners

Access	Constructor and Description
protected	JConsolePlugin() Constructor.

Method Summary

Modifier and Type	Method and Description
public final void	addContextPropertyChangeListener(PropertyChangeListener The `PropertyChangeListener` to be added listener) Adds a `PropertyChangeListener` to the `JConsoleContext` object for this plugin.
public void	dispose() Dispose this plugin.
public final JConsoleContext	Returns: the `JConsoleContext` object representing the connection to an application. getContext() Returns the `JConsoleContext` object representing the connection to an application.
public abstract Map<String, JPanel>	Returns: a map of a tab name and a `JPanel` object representing the tabs to be added in the JConsole window; or an empty map. getTabs() Returns the tabs to be added in JConsole window.
public abstract SwingWorker<?, ?>	Returns: a `SwingWorker` to perform the GUI update; or `null`. newSwingWorker() Returns a `SwingWorker` to perform the GUI update for this plugin at the same interval as JConsole updates the GUI.
public final void	removeContextPropertyChangeListener(PropertyChangeListener the `PropertyChangeListener` to be removed listener) Removes a `PropertyChangeListener` from the listener list of the `JConsoleContext` object for this plugin.
public final synchronized void	setContext(JConsoleContext a `JConsoleContext` object context) Sets the `JConsoleContext` object representing the connection to an application.

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

Field Detail

context	back to summary
private volatile JConsoleContext context

listeners	back to summary
private List<PropertyChangeListener> listeners

Constructor Detail

JConsolePlugin	back to summary
protected JConsolePlugin() Constructor.

Method Detail

addContextPropertyChangeListener back to summary

addContextPropertyChangeListener	back to summary
public final void addContextPropertyChangeListener(PropertyChangeListener listener) Adds a `PropertyChangeListener` to the `JConsoleContext` object for this plugin. This method is a convenient method for this plugin to register a listener when the `JConsoleContext` object may or may not be available. For example, a plugin constructor can call this method to register a listener to listen to the `connectionState` property changes and the listener will be added to the `JConsoleContext` object when it is available. Parameters listener:PropertyChangeListener The `PropertyChangeListener` to be added Exceptions NullPointerException: if `listener` is `null`.

public final void addContextPropertyChangeListener(PropertyChangeListener listener)

Adds a PropertyChangeListener to the JConsoleContext object for this plugin. This method is a convenient method for this plugin to register a listener when the JConsoleContext object may or may not be available.

For example, a plugin constructor can call this method to register a listener to listen to the connectionState property changes and the listener will be added to the JConsoleContext object when it is available.

Parameters

listener:PropertyChangeListener: The PropertyChangeListener to be added

Exceptions

NullPointerException:: if listener is null.

dispose	back to summary
public void dispose() Dispose this plugin. This method is called by JConsole to inform that this plugin will be discarded and that it should free any resources that it has allocated. The `JConsoleContext` can be in any `connection state` when this method is called.

getContext back to summary

getContext	back to summary
public final JConsoleContext getContext() Returns the `JConsoleContext` object representing the connection to an application. This method may return `null` if it is called before the `context` is initialized. Returns:JConsoleContext the `JConsoleContext` object representing the connection to an application.

public final JConsoleContext getContext()

Returns the JConsoleContext object representing the connection to an application. This method may return null if it is called before the context is initialized.

Returns:JConsoleContext: the JConsoleContext object representing the connection to an application.

getTabs back to summary

getTabs	back to summary
public abstract Map<String, JPanel> getTabs() Returns the tabs to be added in JConsole window. The returned map contains one entry for each tab to be added in the tabbed pane in a JConsole window with the tab name as the key and the `JPanel` object as the value. This method returns an empty map if no tab is added by this plugin. This method will be called from the Event Dispatch Thread once at the new connection time. Returns:Map<String, JPanel> a map of a tab name and a `JPanel` object representing the tabs to be added in the JConsole window; or an empty map.

public abstract Map<String, JPanel> getTabs()

Returns the tabs to be added in JConsole window.

The returned map contains one entry for each tab to be added in the tabbed pane in a JConsole window with the tab name as the key and the JPanel object as the value. This method returns an empty map if no tab is added by this plugin. This method will be called from the Event Dispatch Thread once at the new connection time.

Returns:Map<String, JPanel>: a map of a tab name and a JPanel object representing the tabs to be added in the JConsole window; or an empty map.

newSwingWorker back to summary

newSwingWorker	back to summary
public abstract SwingWorker<?, ?> newSwingWorker() Returns a `SwingWorker` to perform the GUI update for this plugin at the same interval as JConsole updates the GUI. JConsole schedules the GUI update at an interval specified for a connection. This method will be called at every update to obtain a `SwingWorker` for each plugin. JConsole will invoke the `execute()` method to schedule the returned `SwingWorker` for execution if: the `SwingWorker` object has not been executed (i.e. the `SwingWorker#getState` method returns `PENDING` state); and the `SwingWorker` object returned in the previous update has completed the task if it was not `null` (i.e. the `SwingWorker.isDone` method returns `true`). Otherwise, `SwingWorker` object will not be scheduled to work. A plugin can schedule its own GUI update and this method will return `null`. Returns:SwingWorker<?, ?> a `SwingWorker` to perform the GUI update; or `null`.

public abstract SwingWorker<?, ?> newSwingWorker()

Returns a SwingWorker to perform the GUI update for this plugin at the same interval as JConsole updates the GUI.

JConsole schedules the GUI update at an interval specified for a connection. This method will be called at every update to obtain a SwingWorker for each plugin.

JConsole will invoke the execute() method to schedule the returned SwingWorker for execution if:

the SwingWorker object has not been executed (i.e. the SwingWorker#getState method returns PENDING state); and
the SwingWorker object returned in the previous update has completed the task if it was not null (i.e. the SwingWorker.isDone method returns true).

Otherwise, SwingWorker object will not be scheduled to work.

A plugin can schedule its own GUI update and this method will return null.

Returns:SwingWorker<?, ?>: a SwingWorker to perform the GUI update; or null.

removeContextPropertyChangeListener back to summary

removeContextPropertyChangeListener	back to summary
public final void removeContextPropertyChangeListener(PropertyChangeListener listener) Removes a `PropertyChangeListener` from the listener list of the `JConsoleContext` object for this plugin. If `listener` was never added, no exception is thrown and no action is taken. Parameters listener:PropertyChangeListener the `PropertyChangeListener` to be removed Exceptions NullPointerException: if `listener` is `null`.

public final void removeContextPropertyChangeListener(PropertyChangeListener listener)

Removes a PropertyChangeListener from the listener list of the JConsoleContext object for this plugin. If listener was never added, no exception is thrown and no action is taken.

Parameters

listener:PropertyChangeListener: the PropertyChangeListener to be removed

Exceptions

NullPointerException:: if listener is null.

setContext back to summary

setContext	back to summary
public final synchronized void setContext(JConsoleContext context) Sets the `JConsoleContext` object representing the connection to an application. This method will be called only once after the plugin is created and before the `getTabs` is called. The given `context` can be in any `connection state` when this method is called. Parameters context:JConsoleContext a `JConsoleContext` object

public final synchronized void setContext(JConsoleContext context)

Sets the JConsoleContext object representing the connection to an application. This method will be called only once after the plugin is created and before the getTabs is called. The given context can be in any connection state when this method is called.

Parameters

context:JConsoleContext: a JConsoleContext object

public abstract Class JConsolePlugin

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail