org.apache.nutch.plugin
Class PluginRepository

java.lang.Object
  org.apache.nutch.plugin.PluginRepository

public class PluginRepository

extends Object

The plugin repositority is a registry of all plugins. At system boot up a repositority is builded by parsing the mainifest files of all plugins. Plugins that require not existing other plugins are not registed. For each plugin a plugin descriptor instance will be created. The descriptor represents all meta information about a plugin. So a plugin instance will be created later when it is required, this allow lazy plugin loading.

Author:

joa23

Field Summary

static Logger

LOG

Method Summary

void	finalize()
ExtensionPoint	getExtensionPoint(String pXpId) Returns a extension point indentified by a extension point id.
static PluginRepository	getInstance() Returns the singelton instance of the PluginRepository
PluginDescriptor	getPluginDescriptor(String pPluginId) Returns the descriptor of one plugin identified by a plugin id.
PluginDescriptor[]	getPluginDescriptors() Returns all registed plugin descriptors.
Plugin	getPluginInstance(PluginDescriptor pDescriptor) Returns a instance of a plugin.

Methods inherited from class java.lang.Object

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

Field Detail

LOG

public static final Logger LOG

Method Detail

getInstance

public static PluginRepository getInstance()

Returns the singelton instance of the PluginRepository

getPluginDescriptors

public PluginDescriptor[] getPluginDescriptors()

Returns all registed plugin descriptors.

Returns:

PluginDescriptor[]

getPluginDescriptor

public PluginDescriptor getPluginDescriptor(String pPluginId)

Returns the descriptor of one plugin identified by a plugin id.

Parameters:

pPluginId -

Returns:

PluginDescriptor

getExtensionPoint

public ExtensionPoint getExtensionPoint(String pXpId)

Returns a extension point indentified by a extension point id.

Parameters:

pXpId -

getPluginInstance

public Plugin getPluginInstance(PluginDescriptor pDescriptor)
                         throws PluginRuntimeException

Returns a instance of a plugin. Plugin instances are cached. So a plugin exist only as one instance. This allow a central management of plugin own resources. After creating the plugin instance the startUp() method is invoked. The plugin use a own classloader that is used as well by all instance of extensions of the same plugin. This class loader use all exported libraries from the dependend plugins and all plugin libraries.

Parameters:

pDescriptor -

Returns:

Plugin

Throws:

PluginRuntimeException

finalize

public void finalize()
              throws Throwable

Throws:

Throwable