Package org.apache.fulcrum.factory

Class DefaultFactoryService

java.lang.Object

org.apache.avalon.framework.logger.AbstractLogEnabled

org.apache.fulcrum.factory.DefaultFactoryService

All Implemented Interfaces:

org.apache.avalon.framework.activity.Disposable, org.apache.avalon.framework.activity.Initializable, org.apache.avalon.framework.configuration.Configurable, org.apache.avalon.framework.logger.LogEnabled, FactoryService

public class DefaultFactoryService
extends org.apache.avalon.framework.logger.AbstractLogEnabled
implements FactoryService, org.apache.avalon.framework.configuration.Configurable, org.apache.avalon.framework.activity.Initializable, org.apache.avalon.framework.activity.Disposable

The Factory Service instantiates objects using specified class loaders. If none is specified, the default one will be used. avalon.component name="factory" lifestyle="singleton" avalon.service type="org.apache.fulcrum.factory.FactoryService"

Version:

$Id$

Author:

Eric Pugh, Ilkka Priha, Stephen McConnell

Field Summary

Fields

Modifier and Type	Field	Description
protected static String	DEFAULT_FACTORY	The name of the default factory.

Fields inherited from interface org.apache.fulcrum.factory.FactoryService

ROLE

Constructor Summary

Constructors

Constructor	Description
DefaultFactoryService()

Method Summary

Modifier and Type	Method	Description
void	configure(org.apache.avalon.framework.configuration.Configuration conf)
void	dispose()	Avalon component lifecycle method Clear lists and maps
protected <T> Factory<T>	getFactory(String className)	Gets a customized factory for a named class.
<T> T	getInstance(Class<T> clazz)	Gets an instance of a specified class.
protected <T> T	getInstance(Class<T> clazz, Object[] params, String[] signature)	Gets an instance of a specified class.
<T> T	getInstance(String className)	Gets an instance of a named class.
<T> T	getInstance(String className, ClassLoader loader)	Gets an instance of a named class using a specified class loader.
<T> T	getInstance(String className, ClassLoader loader, Object[] params, String[] signature)	Gets an instance of a named class using a specified class loader.
<T> T	getInstance(String className, Object[] params, String[] signature)	Gets an instance of a named class.
protected static Class<?>	getPrimitiveClass(String type)	Gets the class of a primitive type.
Class<?>[]	getSignature(Class<?> clazz, Object[] params, String[] signature)	Gets the signature classes for parameters of a method of a class.
void	initialize()	Avalon component lifecycle method Initializes the service by loading default class loaders and customized object factories.
boolean	isLoaderSupported(String className)	Tests if specified class loaders are supported for a named class.
protected <T> Class<T>	loadClass(String className)	Loads the named class using the default class loader.
protected <T> Class<T>	loadClass(String className, ClassLoader loader)	Loads the named class using a specified class loader.
protected Object	switchObjectContext(Object object, ClassLoader loader)	Switches an object into the context of a different class loader.

Methods inherited from class org.apache.avalon.framework.logger.AbstractLogEnabled

enableLogging, getLogger, setupLogger, setupLogger, setupLogger

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_FACTORY

protected static final String DEFAULT_FACTORY

The name of the default factory.

See Also:

Constant Field Values

Constructor Detail

DefaultFactoryService

public DefaultFactoryService()

Method Detail

getPrimitiveClass

protected static Class<?> getPrimitiveClass(String type)

Gets the class of a primitive type.

Parameters:

type - a primitive type.

Returns:

the corresponding class, or null.

getInstance

public <T> T getInstance(String className)
                  throws FactoryException

Gets an instance of a named class.

Specified by:

getInstance in interface FactoryService

Type Parameters:

T - Type of the class

Parameters:

className - the name of the class.

Returns:

the instance.

Throws:

FactoryException - if instantiation fails.

getInstance

public <T> T getInstance(String className,
                         ClassLoader loader)
                  throws FactoryException

Gets an instance of a named class using a specified class loader.

Class loaders are supported only if the isLoaderSupported method returns true. Otherwise the loader parameter is ignored.

Specified by:

getInstance in interface FactoryService

Type Parameters:

T - Type of the class

Parameters:

className - the name of the class.

loader - the class loader.

Returns:

the instance.

Throws:

FactoryException - if instantiation fails.

getInstance

public <T> T getInstance(String className,
                         Object[] params,
                         String[] signature)
                  throws FactoryException

Gets an instance of a named class. Parameters for its constructor are given as an array of objects, primitive types must be wrapped with a corresponding class.

Specified by:

getInstance in interface FactoryService

Type Parameters:

T - Type of the class

Parameters:

className - the name of the class.

params - an array containing the parameters of the constructor.

signature - an array containing the signature of the constructor.

Returns:

the instance.

Throws:

FactoryException - if instantiation fails.

getInstance

public <T> T getInstance(String className,
                         ClassLoader loader,
                         Object[] params,
                         String[] signature)
                  throws FactoryException

Gets an instance of a named class using a specified class loader. Parameters for its constructor are given as an array of objects, primitive types must be wrapped with a corresponding class.

Class loaders are supported only if the isLoaderSupported method returns true. Otherwise the loader parameter is ignored.

Specified by:

getInstance in interface FactoryService

Type Parameters:

T - Type of the class

Parameters:

className - the name of the class.

loader - the class loader.

params - an array containing the parameters of the constructor.

signature - an array containing the signature of the constructor.

Returns:

the instance.

Throws:

FactoryException - if instantiation fails.

isLoaderSupported

public boolean isLoaderSupported(String className)
                          throws FactoryException

Tests if specified class loaders are supported for a named class.

Specified by:

isLoaderSupported in interface FactoryService

Parameters:

className - the name of the class.

Returns:

true if class loaders are supported, false otherwise.

Throws:

FactoryException - if test fails.

getInstance

public <T> T getInstance(Class<T> clazz)
                  throws FactoryException

Gets an instance of a specified class.

Specified by:

getInstance in interface FactoryService

Type Parameters:

T - Type of the class

Parameters:

clazz - the class.

Returns:

the instance.

Throws:

FactoryException - if instantiation fails.

getInstance

protected <T> T getInstance(Class<T> clazz,
                            Object[] params,
                            String[] signature)
                     throws FactoryException

Gets an instance of a specified class. Parameters for its constructor are given as an array of objects, primitive types must be wrapped with a corresponding class.

Type Parameters:

T - Type of the class

Parameters:

clazz - the class

params - an array containing the parameters of the constructor

signature - an array containing the signature of the constructor

Returns:

the instance

Throws:

FactoryException - if instantiation fails.

getSignature

public Class<?>[] getSignature(Class<?> clazz,
                               Object[] params,
                               String[] signature)
                        throws ClassNotFoundException

Gets the signature classes for parameters of a method of a class.

Specified by:

getSignature in interface FactoryService

Parameters:

clazz - the class.

params - an array containing the parameters of the method.

signature - an array containing the signature of the method.

Returns:

an array of signature classes. Note that in some cases objects in the parameter array can be switched to the context of a different class loader.

Throws:

ClassNotFoundException - if any of the classes is not found.

switchObjectContext

protected Object switchObjectContext(Object object,
                                     ClassLoader loader)

Switches an object into the context of a different class loader.

Parameters:

object - an object to switch.

loader - the ClassLoader to use

loader - the loader of the new context.

Returns:

the object

loadClass

protected <T> Class<T> loadClass(String className)
                          throws ClassNotFoundException

Loads the named class using the default class loader.

Parameters:

className - the name of the class to load.

Returns:

the loaded class.

Throws:

ClassNotFoundException - if the class was not found.

loadClass

protected <T> Class<T> loadClass(String className,
                                 ClassLoader loader)
                          throws ClassNotFoundException

Loads the named class using a specified class loader.

Parameters:

className - the name of the class to load.

loader - the loader to use.

Returns:

the loaded class.

Throws:

ClassNotFoundException - if the class was not found.

getFactory

protected <T> Factory<T> getFactory(String className)
                             throws FactoryException

Gets a customized factory for a named class. If no class-specific factory is specified but a default factory is, will use the default factory.

Parameters:

className - the name of the class to load.

Returns:

the factory, or null if not specified and no default.

Throws:

FactoryException - if instantiation of the factory fails.

configure

public void configure(org.apache.avalon.framework.configuration.Configuration conf)
               throws org.apache.avalon.framework.configuration.ConfigurationException

Specified by:

configure in interface org.apache.avalon.framework.configuration.Configurable

Throws:

org.apache.avalon.framework.configuration.ConfigurationException

initialize

public void initialize()
                throws Exception

Avalon component lifecycle method Initializes the service by loading default class loaders and customized object factories.

Specified by:

initialize in interface org.apache.avalon.framework.activity.Initializable

Throws:

Exception - if initialization fails.

dispose

public void dispose()

Avalon component lifecycle method Clear lists and maps

Specified by:

dispose in interface org.apache.avalon.framework.activity.Disposable