Package org.apache.fulcrum.factory

Interface FactoryService

All Known Implementing Classes:

DefaultFactoryService

public interface FactoryService

The Factory Service instantiates objects using either default class loaders or a specified one. Whether specified class loaders are supported for a class depends on implementation and can be tested with the isLoaderSupported method.

Version:

$Id$

Author:

Eric Pugh, Ilkka Priha

Field Summary

Fields

Modifier and Type	Field	Description
static String	ROLE	The key under which this component is known by an avalon container.

Method Summary

Modifier and Type	Method	Description
<T> T	getInstance(Class<T> clazz)	Gets an instance of a 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.
Class<?>[]	getSignature(Class<?> clazz, Object[] params, String[] signature)	Gets the signature classes for parameters of a method of a class.
boolean	isLoaderSupported(String className)	Tests if specified class loaders are supported for a named class.

Field Detail

ROLE

static final String ROLE

The key under which this component is known by an avalon container.

Method Detail

getInstance

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

Gets an instance of a class.

Type Parameters:

T - Type of the class

Parameters:

clazz - the name of the class.

Returns:

the instance.

Throws:

FactoryException - if instantiation fails.

getInstance

<T> T getInstance(String className)
           throws FactoryException

Gets an instance of a named class.

Type Parameters:

T - Type of the class

Parameters:

className - the name of the class.

Returns:

the instance.

Throws:

FactoryException - if instantiation fails.

getInstance

<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.

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

<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.

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

<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.

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

boolean isLoaderSupported(String className)
                   throws FactoryException

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

Parameters:

className - the name of the class.

Returns:

true if class loaders are supported, false otherwise.

Throws:

FactoryException - if test fails.

getSignature

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

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

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.