org.apache.solr.util.plugin

Class AbstractPluginLoader<T>

java.lang.Object

org.apache.solr.util.plugin.AbstractPluginLoader<T>

Direct Known Subclasses:

MapPluginLoader, NamedListPluginLoader

public abstract class AbstractPluginLoader<T>
extends java.lang.Object

An abstract super class that manages standard solr-style plugin configuration.

Since:

solr 1.3

Version:

$Id: AbstractPluginLoader.java 1052938 2010-12-26 20:21:48Z rmuir $

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
private class	AbstractPluginLoader.PluginInitInfo Internal class to hold onto initialization info so that it can be initialized after it is registered.

Field Summary

Fields

Modifier and Type	Field and Description
static org.slf4j.Logger	log
private boolean	preRegister
private boolean	requireName
private java.lang.String	type

Constructor Summary

Constructors

Constructor and Description
AbstractPluginLoader(java.lang.String type)
AbstractPluginLoader(java.lang.String type, boolean preRegister, boolean requireName)

Method Summary

Modifier and Type	Method and Description
protected T	create(ResourceLoader loader, java.lang.String name, java.lang.String className, org.w3c.dom.Node node) Create a plugin from an XML configuration.
protected java.lang.String[]	getDefaultPackages() Where to look for classes
protected abstract void	init(T plugin, org.w3c.dom.Node node) Initialize the plugin.
T	load(ResourceLoader loader, org.w3c.dom.NodeList nodes) Given a NodeList from XML in the form: ...
T	loadSingle(ResourceLoader loader, org.w3c.dom.Node node) Given a NodeList from XML in the form: ...
protected abstract T	register(java.lang.String name, T plugin) Register a plugin with a given name.

Methods inherited from class java.lang.Object

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

Field Detail

log

public static org.slf4j.Logger log

type

private final java.lang.String type

preRegister

private final boolean preRegister

requireName

private final boolean requireName

Constructor Detail

AbstractPluginLoader

public AbstractPluginLoader(java.lang.String type,
                            boolean preRegister,
                            boolean requireName)

Parameters:

type - is the 'type' name included in error messages.

preRegister - if true, this will first register all Plugins, then it will initialize them.

AbstractPluginLoader

public AbstractPluginLoader(java.lang.String type)

Method Detail

getDefaultPackages

protected java.lang.String[] getDefaultPackages()

Where to look for classes

create

protected T create(ResourceLoader loader,
                   java.lang.String name,
                   java.lang.String className,
                   org.w3c.dom.Node node)
            throws java.lang.Exception

Create a plugin from an XML configuration. Plugins are defined using: ...

Parameters:

name - - The registered name. In the above example: "name1"

className - - class name for requested plugin. In the above example: "solr.ClassName"

node - - the XML node defining this plugin

Throws:

java.lang.Exception

register

protected abstract T register(java.lang.String name,
                              T plugin)
                       throws java.lang.Exception

Register a plugin with a given name.

Returns:

The plugin previously registered to this name, or null

Throws:

java.lang.Exception

init

protected abstract void init(T plugin,
                             org.w3c.dom.Node node)
                      throws java.lang.Exception

Initialize the plugin.

Parameters:

plugin - - the plugin to initialize

node - - the XML node defining this plugin

Throws:

java.lang.Exception

load

public T load(ResourceLoader loader,
              org.w3c.dom.NodeList nodes)

Given a NodeList from XML in the form: ... ... This will initialize and register each plugin from the list. A class will be generated for each class name and registered to the given name. If 'preRegister' is true, each plugin will be registered *before* it is initialized This may be useful for implementations that need to inspect other registered plugins at startup. One (and only one) plugin may declare itself to be the 'default' plugin using: If a default element is defined, it will be returned from this function.

loadSingle

public T loadSingle(ResourceLoader loader,
                    org.w3c.dom.Node node)

Given a NodeList from XML in the form: ... This will initialize and register a single plugin. A class will be generated for the plugin and registered to the given name. If 'preRegister' is true, the plugin will be registered *before* it is initialized This may be useful for implementations that need to inspect other registered plugins at startup. The created class for the plugin will be returned from this function.