[TOC]

org.apache.nutch.plugin

Class Plugin

public class Plugin
extends Object

A nutch-plugin is an container for a set of custom logic that provide extensions to the nutch core functionality or another plugin that provides an API for extending. A plugin can provide one or a set of extensions. Extensions are components that can be dynamically installed as a kind of listener to extension points. Extension points are a kind of publisher that provide a API and invoke one or a set of installed extensions. Each plugin may extend the base Plugin. Plugin instances are used as the point of life cycle managemet of plugin related functionality. The Plugin will be startuped and shutdown by the nutch plugin management system. A possible usecase of the Plugin implementation is to create or close a database connection.

  • Author:
  • joa23

Field Summary

Fields Modifier and Type Field and Description protected org.apache.hadoop.conf.Configuration conf

Constructor Summary

Constructors Constructor and Description Plugin(PluginDescriptor pDescriptor, org.apache.hadoop.conf.Configuration conf) Constructor

Method Summary

Methods Modifier and Type Method and Description protected void finalize() PluginDescriptor getDescriptor() Returns the plugin descriptor void shutDown() Shutdown the plugin. void startUp() Will be invoked until plugin start up.

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Methods inherited from class java.lang.Object

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

Field Detail

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conf

protected org.apache.hadoop.conf.Configuration conf

Constructor Detail

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Plugin

public Plugin(PluginDescriptor pDescriptor,
      org.apache.hadoop.conf.Configuration conf)

Constructor

Method Detail

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startUp

public void startUp()
             throws PluginRuntimeException

Will be invoked until plugin start up. Since the nutch-plugin system use lazy loading the start up is invoked until the first time a extension is used.

  - Throws: 
  - <code>PluginRuntimeException</code> - If the startup was without successs.       
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shutDown

public void shutDown()
              throws PluginRuntimeException

Shutdown the plugin. This happens until nutch will be stopped.

  - Throws: 
  - <code>PluginRuntimeException</code> - if a problems occurs until shutdown the plugin.       
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getDescriptor

public PluginDescriptor getDescriptor()

Returns the plugin descriptor

  - Returns:
  - PluginDescriptor       
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finalize

protected void finalize()
                 throws Throwable
  - Overrides: 
  - <code>finalize</code> in class <code>Object</code> 
  - Throws: 
  - <code>Throwable</code>

Copyright © 2014 The Apache Software Foundation