Class AbstractSimpleBeanDefinitionParser
- All Implemented Interfaces:
BeanDefinitionParser
- Direct Known Subclasses:
GroovyMarkupConfigurerBeanDefinitionParser
,ScriptTemplateConfigurerBeanDefinitionParser
Class
being configured.
Extend this parser class when you want to create a single
bean definition from a relatively simple custom XML element. The
resulting BeanDefinition
will be automatically
registered with the relevant
BeanDefinitionRegistry
.
An example will hopefully make the use of this particular parser class immediately clear. Consider the following class definition:
public class SimpleCache implements Cache { public void setName(String name) {...} public void setTimeout(int timeout) {...} public void setEvictionPolicy(EvictionPolicy policy) {...} // remaining class definition elided for clarity... }
Then let us assume the following XML tag has been defined to permit the easy configuration of instances of the above class;
<caching:cache name="..." timeout="..." eviction-policy="..."/>
All that is required of the Java developer tasked with writing
the parser to parse the above XML tag into an actual
SimpleCache
bean definition is the following:
public class SimpleCacheBeanDefinitionParser extends AbstractSimpleBeanDefinitionParser { protected Class getBeanClass(Element element) { return SimpleCache.class; } }
Please note that the AbstractSimpleBeanDefinitionParser
is limited to populating the created bean definition with property values.
if you want to parse constructor arguments and nested elements from the
supplied XML element, then you will have to implement the
postProcess(org.springframework.beans.factory.support.BeanDefinitionBuilder, org.w3c.dom.Element)
method and do such parsing yourself, or (more likely) subclass the
AbstractSingleBeanDefinitionParser
or AbstractBeanDefinitionParser
classes directly.
The process of actually registering the
SimpleCacheBeanDefinitionParser
with the Spring XML parsing
infrastructure is described in the Spring Framework reference documentation
(in one of the appendices).
For an example of this parser in action (so to speak), do look at
the source code for the
UtilNamespaceHandler.PropertiesBeanDefinitionParser
;
the observant (and even not so observant) reader will immediately notice that
there is next to no code in the implementation. The
PropertiesBeanDefinitionParser
populates a
PropertiesFactoryBean
from an XML element that looks like this:
<util:properties location="jdbc.properties"/>
The observant reader will notice that the sole attribute on the
<util:properties/>
element matches the
PropertiesLoaderSupport.setLocation(org.springframework.core.io.Resource)
method name on the PropertiesFactoryBean
(the general
usage thus illustrated holds true for any number of attributes).
All that the PropertiesBeanDefinitionParser
needs
actually do is supply an implementation of the
AbstractSingleBeanDefinitionParser.getBeanClass(org.w3c.dom.Element)
method to return the
PropertiesFactoryBean
type.
- Since:
- 2.0
- Author:
- Rob Harrop, Rick Evans, Juergen Hoeller
- See Also:
-
Field Summary
Fields inherited from class org.springframework.beans.factory.xml.AbstractBeanDefinitionParser
ID_ATTRIBUTE, NAME_ATTRIBUTE
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Constructor Summary
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Method Summary
Modifier and TypeMethodDescriptionprotected void
doParse
(Element element, ParserContext parserContext, BeanDefinitionBuilder builder) Parse the suppliedElement
and populate the suppliedBeanDefinitionBuilder
as required.protected String
extractPropertyName
(String attributeName) Extract a JavaBean property name from the supplied attribute name.protected boolean
isEligibleAttribute
(String attributeName) Determine whether the given attribute is eligible for being turned into a corresponding bean property value.protected boolean
isEligibleAttribute
(Attr attribute, ParserContext parserContext) Determine whether the given attribute is eligible for being turned into a corresponding bean property value.protected void
postProcess
(BeanDefinitionBuilder beanDefinition, Element element) Hook method that derived classes can implement to inspect/change a bean definition after parsing is complete.Methods inherited from class org.springframework.beans.factory.xml.AbstractSingleBeanDefinitionParser
doParse, getBeanClass, getBeanClassName, getParentName, parseInternal
Methods inherited from class org.springframework.beans.factory.xml.AbstractBeanDefinitionParser
parse, postProcessComponentDefinition, registerBeanDefinition, resolveId, shouldFireEvents, shouldGenerateId, shouldGenerateIdAsFallback, shouldParseNameAsAliases
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Constructor Details
-
AbstractSimpleBeanDefinitionParser
public AbstractSimpleBeanDefinitionParser()
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Method Details
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doParse
Parse the suppliedElement
and populate the suppliedBeanDefinitionBuilder
as required.This implementation maps any attributes present on the supplied element to
PropertyValue
instances, andadds them
to thebuilder
.The
extractPropertyName(String)
method is used to reconcile the name of an attribute with the name of a JavaBean property.- Overrides:
doParse
in classAbstractSingleBeanDefinitionParser
- Parameters:
element
- the XML element being parsedbuilder
- used to define theBeanDefinition
parserContext
- the object encapsulating the current state of the parsing process- See Also:
-
isEligibleAttribute
Determine whether the given attribute is eligible for being turned into a corresponding bean property value.The default implementation considers any attribute as eligible, except for the "id" attribute and namespace declaration attributes.
- Parameters:
attribute
- the XML attribute to checkparserContext
- theParserContext
- See Also:
-
isEligibleAttribute
Determine whether the given attribute is eligible for being turned into a corresponding bean property value.The default implementation considers any attribute as eligible, except for the "id" attribute.
- Parameters:
attributeName
- the attribute name taken straight from the XML element being parsed (nevernull
)
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extractPropertyName
Extract a JavaBean property name from the supplied attribute name.The default implementation uses the
Conventions.attributeNameToPropertyName(String)
method to perform the extraction.The name returned must obey the standard JavaBean property name conventions. For example for a class with a setter method '
setBingoHallFavourite(String)
', the name returned had better be 'bingoHallFavourite
' (with that exact casing).- Parameters:
attributeName
- the attribute name taken straight from the XML element being parsed (nevernull
)- Returns:
- the extracted JavaBean property name (must never be
null
)
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postProcess
Hook method that derived classes can implement to inspect/change a bean definition after parsing is complete.The default implementation does nothing.
- Parameters:
beanDefinition
- the parsed (and probably totally defined) bean definition being builtelement
- the XML element that was the source of the bean definition's metadata
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