org.pfsw.plugin

Class PluginRegistry

java.lang.Object

org.pfsw.plugin.PluginRegistry

public class PluginRegistry
extends java.lang.Object

A special registry that is capable to hold any number of plug-ins of any type.

Field Summary

Fields

Modifier and Type	Field and Description
protected static boolean	DEBUG
protected static java.lang.String	DEBUG_PREFIX
protected static java.lang.String	OPTIONS_END
protected static java.lang.String	OPTIONS_START
protected static java.lang.String	PLUGIN_DEF_SEPARATOR
protected static StringPattern	PLUGIN_OPTIONS_PATTERN

Constructor Summary

Constructors

Constructor and Description
PluginRegistry() Initialize the new instance with default values (i.e.

Method Summary

Modifier and Type	Method and Description
protected int	addDefinitionsToRegistry(OrderedProperties<?> definitions)
void	clear() Remove all registered plugins.
protected CollectionUtil	coll()
protected void	debug(java.lang.String text)
protected FileUtil	fileUtil()
protected java.lang.reflect.Method	find_getPluginId_Method(java.lang.Object object)
protected java.lang.String	getIdOfPlugin(java.lang.Object plugin, java.lang.String defaultId)
java.lang.Object	getPlugin(java.lang.String pluginId) Returns the plug-in with the specified ID or null if no such plug-in can be found in the registry.
<T> T	getPlugin(java.lang.String pluginId, java.lang.Class<T> pluginType) Returns the plug-in with the specified ID and the given type or null if no such plug-in can be found in the registry.
protected Classpath	getPluginClasspath() Returns the classpath that is used to lookup any plug-in information files.
java.lang.String[]	getPluginIDsOfType(java.lang.Class<?> pluginType) Returns the IDs of all plug-ins that are of the specified type.
<T> T[]	getPluginsOfType(java.lang.Class<T> pluginType) Returns all plug-ins that are of the specified type.
protected NamedValueList<org.pfsw.plugin.PluginHolder>	getRegistry()
<T> int	loadPluginsByServiceLoader(java.lang.Class<T> pluginType, java.lang.ClassLoader... classLoaders) Utilizes the Java ServiceLoader mechanism to load all plugins implementing the given type into this registry.
int	loadPluginsFrom(java.lang.String filename) Load all plug-ins that are defined in any library in the specified file.
protected boolean	parseAndAddToRegistry(java.lang.String id, java.lang.String pluginDefinition)
protected PluginUtil	plugUtil()
protected int	readPlugins(java.lang.String filename, Classpath classpath) Read all classes specified in the given file, if it exists in the specified classpath element.
protected int	readPluginsFrom(ClasspathElement element, java.lang.String filename)
protected <T> void	registerPlugin(java.lang.Class<T> pluginType, T plugin)
protected boolean	registerPlugin(org.pfsw.plugin.PluginHolder pluginHolder)
protected void	setRegistry(NamedValueList<org.pfsw.plugin.PluginHolder> newValue)
protected StringUtil	str()
protected boolean	validateClass(ClassInfo<?> classInfo)
protected boolean	validateClassFound(ClassInfo<?> classInfo)
protected boolean	validateInstanceCreation(ClassInfo<?> classInfo)

Methods inherited from class java.lang.Object

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

Field Detail

DEBUG

protected static final boolean DEBUG

DEBUG_PREFIX

protected static final java.lang.String DEBUG_PREFIX

See Also:

Constant Field Values

PLUGIN_DEF_SEPARATOR

protected static final java.lang.String PLUGIN_DEF_SEPARATOR

See Also:

Constant Field Values

OPTIONS_START

protected static final java.lang.String OPTIONS_START

See Also:

Constant Field Values

OPTIONS_END

protected static final java.lang.String OPTIONS_END

See Also:

Constant Field Values

PLUGIN_OPTIONS_PATTERN

protected static final StringPattern PLUGIN_OPTIONS_PATTERN

Constructor Detail

PluginRegistry

public PluginRegistry()

Initialize the new instance with default values (i.e. an empty registry).

Method Detail

loadPluginsFrom

public int loadPluginsFrom(java.lang.String filename)

Load all plug-ins that are defined in any library in the specified file.

Parameters:

filename - The name of the file where the plug-in definition is looked-up.

Returns:

The number of plug-ins that have been loaded to the registry

loadPluginsByServiceLoader

public <T> int loadPluginsByServiceLoader(java.lang.Class<T> pluginType,
                                          java.lang.ClassLoader... classLoaders)

Utilizes the Java ServiceLoader mechanism to load all plugins implementing the given type into this registry.

Parameters:

pluginType - The type (i.e. interface) of the plug-in (must not be null).

classLoaders - An optional array of class loaders. The first non-null classloader will be used for the lookup. If none is provided the thread context classloader and the class loader of this class will be tried.

Returns:

The number of plug-ins that have been loaded to the registry

getPlugin

public java.lang.Object getPlugin(java.lang.String pluginId)

Returns the plug-in with the specified ID or null if no such plug-in can be found in the registry. If more than one plug-in is registered under the same ID the result is the first one found.

Parameters:

pluginId - The identifier of the plug-in (must not be null)

Returns:

An instance of the found plug-in or null

getPlugin

public <T> T getPlugin(java.lang.String pluginId,
                       java.lang.Class<T> pluginType)

Returns the plug-in with the specified ID and the given type or null if no such plug-in can be found in the registry.

Parameters:

pluginId - The identifier of the plug-in (must not be null).

pluginType - The type of the plug-in (must not be null).

Returns:

An instance of the found plug-in or null.

getPluginsOfType

public <T> T[] getPluginsOfType(java.lang.Class<T> pluginType)

Returns all plug-ins that are of the specified type. That also implies plug-ins that are subclasses or implementors of the given type.

Parameters:

pluginType - The type the plug-ins to look for must comply with.

Returns:

An array of found plug-in instances (never null).

getPluginIDsOfType

public java.lang.String[] getPluginIDsOfType(java.lang.Class<?> pluginType)

Returns the IDs of all plug-ins that are of the specified type. That also implies plug-ins that are subclasses or implementors of the given type.

Parameters:

pluginType - The type the plug-ins to look for must comply with.

Returns:

An array of IDs (never null).

clear

public void clear()

Remove all registered plugins.

registerPlugin

protected boolean registerPlugin(org.pfsw.plugin.PluginHolder pluginHolder)

registerPlugin

protected <T> void registerPlugin(java.lang.Class<T> pluginType,
                                  T plugin)

getIdOfPlugin

protected java.lang.String getIdOfPlugin(java.lang.Object plugin,
                                         java.lang.String defaultId)

readPlugins

protected int readPlugins(java.lang.String filename,
                          Classpath classpath)

Read all classes specified in the given file, if it exists in the specified classpath element. Add those classes to the registry if they can be instantiated and are of the correct type.

Parameters:

filename - The name of the properties file that contains the class definitions

classpath - The classpath the specified filename to be looked up in

Returns:

The number of plug-ins that have been added to the registry

readPluginsFrom

protected int readPluginsFrom(ClasspathElement element,
                              java.lang.String filename)

addDefinitionsToRegistry

protected int addDefinitionsToRegistry(OrderedProperties<?> definitions)

parseAndAddToRegistry

protected boolean parseAndAddToRegistry(java.lang.String id,
                                        java.lang.String pluginDefinition)

validateClass

protected boolean validateClass(ClassInfo<?> classInfo)

validateClassFound

protected boolean validateClassFound(ClassInfo<?> classInfo)

validateInstanceCreation

protected boolean validateInstanceCreation(ClassInfo<?> classInfo)

find_getPluginId_Method

protected java.lang.reflect.Method find_getPluginId_Method(java.lang.Object object)

getPluginClasspath

protected Classpath getPluginClasspath()

Returns the classpath that is used to lookup any plug-in information files.

getRegistry

protected NamedValueList<org.pfsw.plugin.PluginHolder> getRegistry()

setRegistry

protected void setRegistry(NamedValueList<org.pfsw.plugin.PluginHolder> newValue)

fileUtil

protected FileUtil fileUtil()

str

protected StringUtil str()

coll

protected CollectionUtil coll()

plugUtil

protected PluginUtil plugUtil()

debug

protected void debug(java.lang.String text)