public interface BeanFactory
Definition of an interface for bean factories.
Beans defined in configuration files are not directly created, but by so called bean factories. This additional level of indirection provides for high flexibility in the creation process. For instance one implementation of this interface could be very simple and create a new instance of the specified class for each invocation. A different implementation could cache already created beans and ensure that always the same bean of the given class will be returned - this would be an easy mean for creating singleton objects.
The interface itself is quite simple. There is a single method for creating a
bean of a given class. All necessary parameters are obtained from an also
BeanDeclaration object. It is also possible
(but optional) for a bean factory to declare the default class of the bean it
creates. Then it is not necessary to specify a bean class in the bean
Object createBean(Class<?> beanClass, BeanDeclaration data, Object param) throws Exception
beanClass- the class for the bean
data- the bean declaration object containing all data about the bean to be created
param- an additional parameter that may be passed by calling code; it is up to a concrete implementation how this parameter is evaluated
Exception- if an error occurs (the helper classes for creating beans will catch this unspecific exception and wrap it in a configuration exception)
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