org.springframework.beans.factory.xml

Class AbstractBeanDefinitionParser

java.lang.Object

org.springframework.beans.factory.xml.AbstractBeanDefinitionParser

All Implemented Interfaces:

BeanDefinitionParser

Direct Known Subclasses:

AbstractSingleBeanDefinitionParser

public abstract class AbstractBeanDefinitionParser
extends Object
implements BeanDefinitionParser

Abstract BeanDefinitionParser implementation providing a number of convenience methods and a template method that subclasses must override to provide the actual parsing logic.

Use this BeanDefinitionParser implementation when you want to parse some arbitrarily complex XML into one or more BeanDefinitions. If you just want to parse some XML into a single BeanDefinition, you may wish to consider the simpler convenience extensions of this class, namely AbstractSingleBeanDefinitionParser and AbstractSimpleBeanDefinitionParser.

Since:

2.0

Author:

Rob Harrop, Juergen Hoeller, Rick Evans, Dave Syer

Field Summary

Fields

Modifier and Type	Field and Description
static String	ID_ATTRIBUTE Constant for the "id" attribute
static String	NAME_ATTRIBUTE Constant for the "name" attribute

Constructor Summary

Constructors

Constructor and Description
AbstractBeanDefinitionParser()

Method Summary

Modifier and Type	Method and Description
BeanDefinition	parse(Element element, ParserContext parserContext) Parse the specified Element and register the resulting BeanDefinition(s) with the BeanDefinitionRegistry embedded in the supplied ParserContext.
protected abstract AbstractBeanDefinition	parseInternal(Element element, ParserContext parserContext) Central template method to actually parse the supplied Element into one or more BeanDefinitions.
protected void	postProcessComponentDefinition(BeanComponentDefinition componentDefinition) Hook method called after the primary parsing of a BeanComponentDefinition but before the BeanComponentDefinition has been registered with a BeanDefinitionRegistry.
protected void	registerBeanDefinition(BeanDefinitionHolder definition, BeanDefinitionRegistry registry) Register the supplied bean with the supplied registry.
protected String	resolveId(Element element, AbstractBeanDefinition definition, ParserContext parserContext) Resolve the ID for the supplied BeanDefinition.
protected boolean	shouldFireEvents() Determine whether this parser is supposed to fire a BeanComponentDefinition event after parsing the bean definition.
protected boolean	shouldGenerateId() Should an ID be generated instead of read from the passed in Element?
protected boolean	shouldGenerateIdAsFallback() Should an ID be generated instead if the passed in Element does not specify an "id" attribute explicitly?
protected boolean	shouldParseNameAsAliases() Determine whether the element's "name" attribute should get parsed as bean definition aliases, i.e.

Methods inherited from class java.lang.Object

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

Field Detail

ID_ATTRIBUTE

public static final String ID_ATTRIBUTE

Constant for the "id" attribute

See Also:

Constant Field Values

NAME_ATTRIBUTE

public static final String NAME_ATTRIBUTE

Constant for the "name" attribute

See Also:

Constant Field Values

Constructor Detail

AbstractBeanDefinitionParser

public AbstractBeanDefinitionParser()

Method Detail

parse

@Nullable
public final BeanDefinition parse(Element element,
                                            ParserContext parserContext)

Description copied from interface: BeanDefinitionParser

Parse the specified Element and register the resulting BeanDefinition(s) with the BeanDefinitionRegistry embedded in the supplied ParserContext.

Implementations must return the primary BeanDefinition that results from the parse if they will ever be used in a nested fashion (for example as an inner tag in a <property/> tag). Implementations may return null if they will not be used in a nested fashion.

Specified by:

parse in interface BeanDefinitionParser

Parameters:

element - the element that is to be parsed into one or more BeanDefinitions

parserContext - the object encapsulating the current state of the parsing process; provides access to a BeanDefinitionRegistry

Returns:

the primary BeanDefinition

resolveId

protected String resolveId(Element element,
                           AbstractBeanDefinition definition,
                           ParserContext parserContext)
                    throws BeanDefinitionStoreException

Resolve the ID for the supplied BeanDefinition.

When using generation, a name is generated automatically. Otherwise, the ID is extracted from the "id" attribute, potentially with a fallback to a generated id.

Parameters:

element - the element that the bean definition has been built from

definition - the bean definition to be registered

parserContext - the object encapsulating the current state of the parsing process; provides access to a BeanDefinitionRegistry

Returns:

the resolved id

Throws:

BeanDefinitionStoreException - if no unique name could be generated for the given bean definition

registerBeanDefinition

protected void registerBeanDefinition(BeanDefinitionHolder definition,
                                      BeanDefinitionRegistry registry)

Register the supplied bean with the supplied registry.

Subclasses can override this method to control whether or not the supplied bean is actually even registered, or to register even more beans.

The default implementation registers the supplied bean with the supplied registry only if the isNested parameter is false, because one typically does not want inner beans to be registered as top level beans.

Parameters:

definition - the bean definition to be registered

registry - the registry that the bean is to be registered with

See Also:

BeanDefinitionReaderUtils.registerBeanDefinition(BeanDefinitionHolder, BeanDefinitionRegistry)

parseInternal

@Nullable
protected abstract AbstractBeanDefinition parseInternal(Element element,
                                                                  ParserContext parserContext)

Central template method to actually parse the supplied Element into one or more BeanDefinitions.

Parameters:

element - the element that is to be parsed into one or more BeanDefinitions

parserContext - the object encapsulating the current state of the parsing process; provides access to a BeanDefinitionRegistry

Returns:

the primary BeanDefinition resulting from the parsing of the supplied Element

See Also:

parse(org.w3c.dom.Element, ParserContext), postProcessComponentDefinition(org.springframework.beans.factory.parsing.BeanComponentDefinition)

shouldGenerateId

protected boolean shouldGenerateId()

Should an ID be generated instead of read from the passed in Element?

Disabled by default; subclasses can override this to enable ID generation. Note that this flag is about always generating an ID; the parser won't even check for an "id" attribute in this case.

Returns:

whether the parser should always generate an id

shouldGenerateIdAsFallback

protected boolean shouldGenerateIdAsFallback()

Should an ID be generated instead if the passed in Element does not specify an "id" attribute explicitly?

Disabled by default; subclasses can override this to enable ID generation as fallback: The parser will first check for an "id" attribute in this case, only falling back to a generated ID if no value was specified.

Returns:

whether the parser should generate an id if no id was specified

shouldParseNameAsAliases

protected boolean shouldParseNameAsAliases()

Determine whether the element's "name" attribute should get parsed as bean definition aliases, i.e. alternative bean definition names.

The default implementation returns true.

Returns:

whether the parser should evaluate the "name" attribute as aliases

Since:

4.1.5

shouldFireEvents

protected boolean shouldFireEvents()

Determine whether this parser is supposed to fire a BeanComponentDefinition event after parsing the bean definition.

This implementation returns true by default; that is, an event will be fired when a bean definition has been completely parsed. Override this to return false in order to suppress the event.

Returns:

true in order to fire a component registration event after parsing the bean definition; false to suppress the event

See Also:

postProcessComponentDefinition(org.springframework.beans.factory.parsing.BeanComponentDefinition), ReaderContext.fireComponentRegistered(org.springframework.beans.factory.parsing.ComponentDefinition)

postProcessComponentDefinition

protected void postProcessComponentDefinition(BeanComponentDefinition componentDefinition)

Hook method called after the primary parsing of a BeanComponentDefinition but before the BeanComponentDefinition has been registered with a BeanDefinitionRegistry.

Derived classes can override this method to supply any custom logic that is to be executed after all the parsing is finished.

The default implementation is a no-op.

Parameters:

componentDefinition - the BeanComponentDefinition that is to be processed