org.datanucleus.plugin

Class PluginManager

java.lang.Object

org.datanucleus.plugin.PluginManager

public class PluginManager
extends Object

Manages the registry of Extensions and Extension Points for the plugin mechanism.

Constructor Summary

Constructors

Constructor and Description
PluginManager(String registryClassName, ClassLoaderResolver clr, Properties props) Constructor.

Method Summary

Modifier and Type	Method and Description
Object	createExecutableExtension(String extensionPoint, String[] discrimAttrName, String[] discrimAttrValue, String attributeName, Class[] argsClass, Object[] args) Convenience accessor for getting the Class of an attribute for an extension (of an extension point).
Object	createExecutableExtension(String extensionPoint, String discrimAttrName, String discrimAttrValue, String attributeName, Class[] argsClass, Object[] args) Convenience accessor for getting the Class of an attribute for an extension (of an extension point).
static PluginManager	createPluginManager(Map props, ClassLoader loader) Convenience method that will create and return a PluginManager using any passed in properties.
String	getAttributeValueForExtension(String extensionPoint, String[] discrimAttrName, String[] discrimAttrValue, String attributeName) Convenience accessor for getting the value of an attribute for an extension (of an extension point).
String	getAttributeValueForExtension(String extensionPoint, String discrimAttrName, String discrimAttrValue, String attributeName) Convenience accessor for getting the value of an attribute for an extension (of an extension point).
String[]	getAttributeValuesForExtension(String extensionPoint, String discrimAttrName, String discrimAttrValue, String attributeName) Convenience accessor for getting the value of an attribute for an extension (of an extension point).
ConfigurationElement	getConfigurationElementForExtension(String extensionPointName, String[] discrimAttrName, String[] discrimAttrValue) Convenience accessor for getting the ConfigurationElement for an extension (of an extension point).
ConfigurationElement	getConfigurationElementForExtension(String extensionPointName, String discrimAttrName, String discrimAttrValue) Convenience accessor for getting the (first) ConfigurationElement for an extension (of an extension point).
ConfigurationElement[]	getConfigurationElementsForExtension(String extensionPointName, String discrimAttrName, String discrimAttrValue) Convenience accessor for getting the ConfigurationElement(s) for an extension (of an extension point).
ExtensionPoint	getExtensionPoint(String id) Acessor for the ExtensionPoint
String	getRegistryClassName() Accessor for the PluginRegistry class name.
String	getVersionForBundle(String bundleName) Accessor for the version of a particular bundle (or null if not registered).
Class	loadClass(String pluginId, String className) Loads a class (do not initialize)
URL	resolveURLAsFileURL(URL url) Converts a URL that uses a user-defined protocol into a URL that uses the file protocol.

Methods inherited from class java.lang.Object

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

Constructor Detail

PluginManager

public PluginManager(String registryClassName,
                     ClassLoaderResolver clr,
                     Properties props)

Constructor.

Parameters:

registryClassName - Name of the registry

clr - the ClassLoaderResolver

props - Configuration properties for the plugin system

Method Detail

getRegistryClassName

public String getRegistryClassName()

Accessor for the PluginRegistry class name.

Returns:

Name of the plugin registry

getExtensionPoint

public ExtensionPoint getExtensionPoint(String id)

Acessor for the ExtensionPoint

Parameters:

id - the unique id of the extension point

Returns:

null if the ExtensionPoint is not registered

getConfigurationElementForExtension

public ConfigurationElement getConfigurationElementForExtension(String extensionPointName,
                                                                String discrimAttrName,
                                                                String discrimAttrValue)

Convenience accessor for getting the (first) ConfigurationElement for an extension (of an extension point).

Parameters:

extensionPointName - The extension point

discrimAttrName - Attribute on the extension to use as discriminator

discrimAttrValue - Value for discriminator attribute

Returns:

The configuration element

getConfigurationElementsForExtension

public ConfigurationElement[] getConfigurationElementsForExtension(String extensionPointName,
                                                                   String discrimAttrName,
                                                                   String discrimAttrValue)

Convenience accessor for getting the ConfigurationElement(s) for an extension (of an extension point).

Parameters:

extensionPointName - The extension point

discrimAttrName - Attribute on the extension to use as discriminator

discrimAttrValue - Value for discriminator attribute

Returns:

Configuration elements

getConfigurationElementForExtension

public ConfigurationElement getConfigurationElementForExtension(String extensionPointName,
                                                                String[] discrimAttrName,
                                                                String[] discrimAttrValue)

Convenience accessor for getting the ConfigurationElement for an extension (of an extension point).

Parameters:

extensionPointName - The extension point

discrimAttrName - Attribute on the extension to use as discriminator1

discrimAttrValue - Value for discriminator1 attribute

Returns:

Configuration Element

getAttributeValueForExtension

public String getAttributeValueForExtension(String extensionPoint,
                                            String discrimAttrName,
                                            String discrimAttrValue,
                                            String attributeName)

Convenience accessor for getting the value of an attribute for an extension (of an extension point).

Parameters:

extensionPoint - The extension point

discrimAttrName - Attribute on the extension to use as discriminator

discrimAttrValue - Value for discriminator attribute

attributeName - Name of the attribute whose value we want

Returns:

The value of the attribute

getAttributeValuesForExtension

public String[] getAttributeValuesForExtension(String extensionPoint,
                                               String discrimAttrName,
                                               String discrimAttrValue,
                                               String attributeName)

Convenience accessor for getting the value of an attribute for an extension (of an extension point).

Parameters:

extensionPoint - The extension point

discrimAttrName - Attribute on the extension to use as discriminator

discrimAttrValue - Value for discriminator attribute

attributeName - Name of the attribute whose value we want

Returns:

The value(s) of the attribute

getAttributeValueForExtension

public String getAttributeValueForExtension(String extensionPoint,
                                            String[] discrimAttrName,
                                            String[] discrimAttrValue,
                                            String attributeName)

Convenience accessor for getting the value of an attribute for an extension (of an extension point).

Parameters:

extensionPoint - The extension point

discrimAttrName - Attribute on the extension to use as discriminator1

discrimAttrValue - Value for discriminator1 attribute

attributeName - Name of the attribute whose value we want

Returns:

The value of the attribute

createExecutableExtension

public Object createExecutableExtension(String extensionPoint,
                                        String discrimAttrName,
                                        String discrimAttrValue,
                                        String attributeName,
                                        Class[] argsClass,
                                        Object[] args)
                                 throws ClassNotFoundException,
                                        NoSuchMethodException,
                                        InstantiationException,
                                        IllegalAccessException,
                                        InvocationTargetException

Convenience accessor for getting the Class of an attribute for an extension (of an extension point).

Parameters:

extensionPoint - The extension point

discrimAttrName - Attribute on the extension to use as discriminator

discrimAttrValue - Value for discriminator attribute

attributeName - Name of the attribute whose value we want

argsClass - Classes of the arguments

args - The arguments

Returns:

The value of the attribute

Throws:

ClassNotFoundException - if an error occurs

NoSuchMethodException - if an error occurs

InstantiationException - if an error occurs

IllegalAccessException - if an error occurs

InvocationTargetException - if an error occurs

createExecutableExtension

public Object createExecutableExtension(String extensionPoint,
                                        String[] discrimAttrName,
                                        String[] discrimAttrValue,
                                        String attributeName,
                                        Class[] argsClass,
                                        Object[] args)
                                 throws ClassNotFoundException,
                                        NoSuchMethodException,
                                        InstantiationException,
                                        IllegalAccessException,
                                        InvocationTargetException

Convenience accessor for getting the Class of an attribute for an extension (of an extension point).

Parameters:

extensionPoint - The extension point

discrimAttrName - First attribute on the extension to use as discriminator

discrimAttrValue - Value for first discriminator attribute

attributeName - Name of the attribute whose value we want

argsClass - Classes of the arguments

args - The arguments

Returns:

The value of the attribute

Throws:

ClassNotFoundException - if an error occurs

NoSuchMethodException - if an error occurs

InstantiationException - if an error occurs

IllegalAccessException - if an error occurs

InvocationTargetException - if an error occurs

loadClass

public Class loadClass(String pluginId,
                       String className)
                throws ClassNotResolvedException

Loads a class (do not initialize)

Parameters:

pluginId - the plugin id

className - the class name

Returns:

the Class

Throws:

ClassNotResolvedException - if an error occurs

resolveURLAsFileURL

public URL resolveURLAsFileURL(URL url)
                        throws IOException

Converts a URL that uses a user-defined protocol into a URL that uses the file protocol.

Parameters:

url - the url to be converted

Returns:

the converted URL

Throws:

IOException - if an error occurs

getVersionForBundle

public String getVersionForBundle(String bundleName)

Accessor for the version of a particular bundle (or null if not registered).

Parameters:

bundleName - Name of the bundle

Returns:

The version

createPluginManager

public static PluginManager createPluginManager(Map props,
                                                ClassLoader loader)

Convenience method that will create and return a PluginManager using any passed in properties. Supports the following properties

• datanucleus.primaryClassLoader
• datanucleus.plugin.pluginRegistryClassName
• datanucleus.plugin.pluginRegistryBundleCheck
• datanucleus.plugin.allowUserBundles
• datanucleus.plugin.validatePlugins

Parameters:

props - Any properties defining the plugin manager capabilities

loader - Any class loader to make use of when loading

Returns:

The PluginManager