Package org.apache.solr.util.plugin

Class AbstractPluginLoader<T>

java.lang.Object

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

Direct Known Subclasses:

FieldTypePluginLoader, MapPluginLoader, NamedListPluginLoader

public abstract class AbstractPluginLoader<T>
extends Object

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

Since:

solr 1.3

Constructor Summary

Constructors

Constructor	Description
AbstractPluginLoader(String type, Class<T> pluginClassType)
AbstractPluginLoader(String type, Class<T> pluginClassType, boolean preRegister, boolean requireName)

Method Summary

Modifier and Type	Method	Description
protected T	create(org.apache.solr.common.cloud.SolrClassLoader loader, String name, String className, org.apache.solr.common.ConfigNode node)	Create a plugin from an XML configuration.
protected String[]	getDefaultPackages()	Where to look for classes
protected abstract void	init(T plugin, org.apache.solr.common.ConfigNode node)	Initialize the plugin.
T	load(org.apache.solr.common.cloud.SolrClassLoader loader, List<org.apache.solr.common.ConfigNode> nodes)	Initializes and registers each plugin in the list.
T	loadSingle(org.apache.solr.common.cloud.SolrClassLoader loader, org.apache.solr.common.ConfigNode node)	Initializes and registers a single plugin.
protected abstract T	register(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

Constructor Detail

AbstractPluginLoader

public AbstractPluginLoader(String type,
                            Class<T> pluginClassType,
                            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(String type,
                            Class<T> pluginClassType)

Method Detail

getDefaultPackages

protected String[] getDefaultPackages()

Where to look for classes

create

protected T create(org.apache.solr.common.cloud.SolrClassLoader loader,
                   String name,
                   String className,
                   org.apache.solr.common.ConfigNode node)
            throws Exception

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

 <plugin name="name1" class="solr.ClassName">
      ...
 </plugin>
 

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:

Exception

register

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

Register a plugin with a given name.

Returns:

The plugin previously registered to this name, or null

Throws:

Exception

init

protected abstract void init(T plugin,
                             org.apache.solr.common.ConfigNode node)
                      throws Exception

Initialize the plugin.

Parameters:

plugin - - the plugin to initialize

node - - the XML node defining this plugin

Throws:

Exception

load

public T load(org.apache.solr.common.cloud.SolrClassLoader loader,
              List<org.apache.solr.common.ConfigNode> nodes)

Initializes and registers each plugin in the list. Given a NodeList from XML in the form:

 <plugins>
    <plugin name="name1" class="solr.ClassName" >
      ...
    </plugin>
    <plugin name="name2" class="solr.ClassName" >
      ...
    </plugin>
 </plugins>
 

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:

 <plugin name="name2" class="solr.ClassName" default="true">
 

If a default element is defined, it will be returned from this function.

loadSingle

public T loadSingle(org.apache.solr.common.cloud.SolrClassLoader loader,
                    org.apache.solr.common.ConfigNode node)

Initializes and registers a single plugin.

Given a NodeList from XML in the form:

 <plugin name="name1" class="solr.ClassName" > ... </plugin>
 

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.