| Interface | Description |
|---|---|
| Pluggable |
Defines the capability of a class to be plugged into Nutch.
|
| Class | Description |
|---|---|
| Extension |
An
Extension is a kind of listener descriptor that will be
installed on a concrete ExtensionPoint that acts as kind of
Publisher. |
| ExtensionPoint |
The
ExtensionPoint provide meta information of a extension
point. |
| Plugin |
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.
|
| PluginClassLoader |
The
PluginClassLoader is a child-first classloader that only
contains classes of the runtime libraries setuped in the plugin manifest file
and exported libraries of plugins that are required plugins. |
| PluginDescriptor |
The
PluginDescriptor provide access to all meta information of a
nutch-plugin, as well to the internationalizable resources and the plugin own
classloader. |
| PluginManifestParser |
The
PluginManifestParser parser just parse the manifest file in
all plugin directories. |
| PluginRepository |
The plugin repositority is a registry of all plugins.
|
| Exception | Description |
|---|---|
| CircularDependencyException |
CircularDependencyException will be thrown if a circular
dependency is detected. |
| MissingDependencyException |
MissingDependencyException will be thrown if a plugin dependency
cannot be found. |
| PluginRuntimeException |
PluginRuntimeException will be thrown until a exception in the
plugin managemnt occurs. |
Plugin System.
The Nutch Plugin System provides a way to extend nutch functionality. A large part of the functionality of Nutch are provided by plugins: All of the parsing, indexing and searching that nutch does is actually accomplished by various plugins.
In writing a plugin, you're actually providing one or more extensions of the
existing extension-points (hooks).
The core Nutch extension-points are themselves defined in a plugin,
the nutch-extensionpoints plugin.
Each extension-point defines an interface that must be implemented by the
extension. The core extension-points and extensions available in Nutch are
listed in the Pluggable interface.
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