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An implementation of the BeanDeclaration interface that is
suitable for XML configuration files.
This class defines the standard layout of a bean declaration in an XML
configuration file. Such a declaration must look like the following example
fragement:
...
<personBean config-class="my.model.PersonBean"
lastName="Doe" firstName="John">
<address config-class="my.model.AddressBean"
street="21st street 11" zip="1234"
city="TestCity"/>
</personBean>
The bean declaration can be contained in an arbitrary element. Here it is the
<personBean> element. In the attributes of this element
there can occur some reserved attributes, which have the following meaning:
config-class- Here the full qualified name of the bean's class can be specified. An
instance of this class will be created. If this attribute is not specified,
the bean class must be provided in another way, e.g. as the
defaultClass passed to the BeanHelper class.
config-factory- This attribute can contain the name of the
BeanFactory that should be used for creating the bean.
If it is defined, a factory with this name must have been registered at the
BeanHelper class. If this attribute is missing, the default
bean factory will be used.
config-factoryParam- With this attribute a parameter can be specified that will be passed to
the bean factory. This may be useful for custom bean factories.
All further attributes starting with the config- prefix are
considered as meta data and will be ignored. All other attributes are treated
as properties of the bean to be created, i.e. corresponding setter methods of
the bean will be invoked with the values specified here.
If the bean to be created has also some complex properties (which are itself
beans), their values cannot be initialized from attributes. For this purpose
nested elements can be used. The example listing shows how an address bean
can be initialized. This is done in a nested element whose name must match
the name of a property of the enclosing bean declaration. The format of this
nested element is exactly the same as for the bean declaration itself, i.e.
it can have attributes defining meta data or bean properties and even further
nested elements for complex bean properties.
A XMLBeanDeclaration object is usually created from a
HierarchicalConfiguration. From this it will derive a
SubnodeConfiguration, which is used to access the needed
properties. This subnode configuration can be obtained using the
XMLBeanDeclaration.getConfiguration() method. All of its properties can
be accessed in the usual way. To ensure that the property keys used by this
class are understood by the configuration, the default expression engine will
be set.
since:
1.3
author:
Oliver Heger
version:
$Id: XMLBeanDeclaration.java 439648 2006-09-02 20:42:10Z oheger $ | 