de.deepamehta.core.impl
Class PluginManager

Show UML class diagram

java.lang.Object
  de.deepamehta.core.impl.PluginManager

 class PluginManager
extends Object

Activates and deactivates plugins and keeps a pool of activated plugins. The pool of activated plugins is a shared resource. All access to it is synchronized.

A PluginManager singleton is hold by the EmbeddedService and is accessed concurrently by all bundle activation threads (as created e.g. by the File Install bundle).

Field Summary

private Map<String,PluginImpl>	activatedPlugins The pool of activated plugins.
private EmbeddedService	dms
private Logger	logger

Constructor Summary

PluginManager(EmbeddedService dms)

Method Summary

private void	_activatePlugin(PluginImpl plugin) Activates a plugin.
private boolean	_isPluginActivated(String pluginUri)
(package private) void	activatePlugin(PluginImpl plugin) Activates a plugin and fires activation events.
private void	addToActivatedPlugins(PluginImpl plugin)
private boolean	checkAllPluginsActivated() Checks if all plugins are activated.
(package private) void	deactivatePlugin(PluginImpl plugin)
(package private) PluginImpl	getPlugin(String pluginUri)
(package private) List<PluginInfo>	getPluginInfo()
private boolean	isDeepaMehtaPlugin(Bundle bundle) Plugin detection: checks if an arbitrary bundle is a DeepaMehta plugin.
(package private) boolean	isPluginActivated(String pluginUri)
private void	removeFromActivatedPlugins(String pluginUri)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

activatedPlugins

private Map<String,PluginImpl> activatedPlugins

The pool of activated plugins. Hashed by plugin bundle's symbolic name, e.g. "de.deepamehta.topicmaps".

dms

private EmbeddedService dms

logger

private Logger logger

Constructor Detail

PluginManager

PluginManager(EmbeddedService dms)

Method Detail

activatePlugin

void activatePlugin(PluginImpl plugin)

Activates a plugin and fires activation events. Called once the plugin's requirements are met (see PluginImpl.checkRequirementsForActivation()).

After activation posts the PLUGIN_ACTIVATED OSGi event. Then checks if all installed plugins are active, and if so, fires the CoreEvent.ALL_PLUGINS_ACTIVE core event.

If the plugin is already activated, performs nothing. This happens e.g. when a dependent plugin is redeployed.

Note: this method is synchronized. While a plugin is activated no other plugin must be activated. Otherwise the "type introduction" mechanism might miss some types. Consider this unsynchronized scenario: plugin B starts running its migrations just in the moment between plugin A's type introduction and event listener registration. Plugin A might miss some of the types created by plugin B.

deactivatePlugin

void deactivatePlugin(PluginImpl plugin)

isPluginActivated

boolean isPluginActivated(String pluginUri)

getPlugin

PluginImpl getPlugin(String pluginUri)

getPluginInfo

List<PluginInfo> getPluginInfo()

_activatePlugin

private void _activatePlugin(PluginImpl plugin)

Activates a plugin. Activation comprises: - install the plugin in the database (includes migrations, post-install event, type introduction) - initialize the plugin - register the plugin's event listeners - register the plugin's OSGi service - add the plugin to the pool of activated plugins

checkAllPluginsActivated

private boolean checkAllPluginsActivated()

Checks if all plugins are activated.

isDeepaMehtaPlugin

private boolean isDeepaMehtaPlugin(Bundle bundle)

Plugin detection: checks if an arbitrary bundle is a DeepaMehta plugin.

addToActivatedPlugins

private void addToActivatedPlugins(PluginImpl plugin)

removeFromActivatedPlugins

private void removeFromActivatedPlugins(String pluginUri)

_isPluginActivated

private boolean _isPluginActivated(String pluginUri)