org.springframework.beans.factory.xml

## Class DefaultBeanDefinitionDocumentReader

- java.lang.Object
- - org.springframework.beans.factory.xml.DefaultBeanDefinitionDocumentReader

All Implemented Interfaces:
  BeanDefinitionDocumentReader

    public class DefaultBeanDefinitionDocumentReader
    extends Object
    implements BeanDefinitionDocumentReader

Default implementation of the `BeanDefinitionDocumentReader` interface. Reads bean definitions according to the "spring-beans" DTD and XSD format (Spring's default XML bean definition format).

The structure, elements and attribute names of the required XML document are hard-coded in this class. (Of course a transform could be run if necessary to produce this format). `&lt;beans&gt;` doesn't need to be the root element of the XML document: This class will parse all bean definition elements in the XML file, not regarding the actual root element.

Since:
  18.12.2003
Author:
  Rod Johnson, Juergen Hoeller, Rob Harrop, Erik Wiersma

### Field Summary

Fields
`static String` `ALIAS_ATTRIBUTE`
`static String` `ALIAS_ELEMENT`
`static String` `BEAN_ELEMENT`
`static String` `IMPORT_ELEMENT`
`protected Log` `logger`
`static String` `NAME_ATTRIBUTE`
`static String` `NESTED_BEANS_ELEMENT`
`static String` `PROFILE_ATTRIBUTE`
`static String` `RESOURCE_ATTRIBUTE`

### Constructor Summary

Constructors
Constructor and Description
`DefaultBeanDefinitionDocumentReader()`

### Method Summary

Methods
`protected BeanDefinitionParserDelegate` `createHelper(XmlReaderContext readerContext, Element root, BeanDefinitionParserDelegate parentDelegate)`
`protected void` `doRegisterBeanDefinitions(Element root)` Register each bean definition within the given root `<beans/>` element.
`protected Object` `extractSource(Element ele)` Invoke the `SourceExtractor` to pull the source metadata from the supplied `Element`.
`protected XmlReaderContext` `getReaderContext()` Return the descriptor for the XML resource that this parser works on.
`protected void` `importBeanDefinitionResource(Element ele)` Parse an "import" element and load the bean definitions from the given resource into the bean factory.
`protected void` `parseBeanDefinitions(Element root, BeanDefinitionParserDelegate delegate)` Parse the elements at the root level in the document: "import", "alias", "bean".
`protected void` `postProcessXml(Element root)` Allow the XML to be extensible by processing any custom element types last, after we finished processing the bean definitions.
`protected void` `preProcessXml(Element root)` Allow the XML to be extensible by processing any custom element types first, before we start to process the bean definitions.
`protected void` `processAliasRegistration(Element ele)` Process the given alias element, registering the alias with the registry.
`protected void` `processBeanDefinition(Element ele, BeanDefinitionParserDelegate delegate)` Process the given bean element, parsing the bean definition and registering it with the registry.
`void` `registerBeanDefinitions(Document doc, XmlReaderContext readerContext)` Read bean definitions from the given DOM document, and register them with the given bean factory.
`void` `setEnvironment(Environment environment)` Set the Environment to use when reading bean definitions.

### Methods inherited from class java.lang.Object

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

### Field Detail

#### BEAN_ELEMENT

    public static final String BEAN_ELEMENT

See Also:
  Constant Field Values

#### NESTED_BEANS_ELEMENT

    public static final String NESTED_BEANS_ELEMENT

See Also:
  Constant Field Values

#### ALIAS_ELEMENT

    public static final String ALIAS_ELEMENT

See Also:
  Constant Field Values

#### NAME_ATTRIBUTE

    public static final String NAME_ATTRIBUTE

See Also:
  Constant Field Values

#### ALIAS_ATTRIBUTE

    public static final String ALIAS_ATTRIBUTE

See Also:
  Constant Field Values

#### IMPORT_ELEMENT

    public static final String IMPORT_ELEMENT

See Also:
  Constant Field Values

#### RESOURCE_ATTRIBUTE

    public static final String RESOURCE_ATTRIBUTE

See Also:
  Constant Field Values

#### PROFILE_ATTRIBUTE

    public static final String PROFILE_ATTRIBUTE

See Also:
  `Profile`, Constant Field Values

#### logger

    protected final Log logger

### Constructor Detail

#### DefaultBeanDefinitionDocumentReader

    public DefaultBeanDefinitionDocumentReader()

### Method Detail

#### setEnvironment

    public void setEnvironment(Environment environment)

Set the Environment to use when reading bean definitions. Used for evaluating profile information to determine whether a `<beans/>` document/element should be included or omitted.

Default value is `null`; property is required for parsing any `<beans/>` element with a `profile` attribute present.

Specified by:
  `setEnvironment` in interface `BeanDefinitionDocumentReader`
See Also:
  `doRegisterBeanDefinitions(org.w3c.dom.Element)`

#### registerBeanDefinitions

    public void registerBeanDefinitions(Document doc,
                               XmlReaderContext readerContext)

Read bean definitions from the given DOM document, and register them with the given bean factory.

This implementation parses bean definitions according to the "spring-beans" XSD (or DTD, historically).

Opens a DOM Document; then initializes the default settings specified at the `<beans/>` level; then parses the contained bean definitions.

Specified by:
  `registerBeanDefinitions` in interface `BeanDefinitionDocumentReader`
Parameters:
  `doc` - the DOM document
  `readerContext` - the current context of the reader. Includes the resource being parsed

#### doRegisterBeanDefinitions

    protected void doRegisterBeanDefinitions(Element root)

Register each bean definition within the given root `<beans/>` element.

Throws:
  `IllegalStateException` - if `<beans profile="..."` attribute is present and Environment property has not been set
See Also:
  `setEnvironment(org.springframework.core.env.Environment)`

#### createHelper

    protected BeanDefinitionParserDelegate createHelper(XmlReaderContext readerContext,
                                            Element root,
                                            BeanDefinitionParserDelegate parentDelegate)

#### getReaderContext

    protected final XmlReaderContext getReaderContext()

Return the descriptor for the XML resource that this parser works on.

#### extractSource

    protected Object extractSource(Element ele)

Invoke the `SourceExtractor` to pull the source metadata from the supplied `Element`.

#### parseBeanDefinitions

    protected void parseBeanDefinitions(Element root,
                            BeanDefinitionParserDelegate delegate)

Parse the elements at the root level in the document: "import", "alias", "bean".

Parameters:
  `root` - the DOM root element of the document

#### importBeanDefinitionResource

    protected void importBeanDefinitionResource(Element ele)

Parse an "import" element and load the bean definitions from the given resource into the bean factory.

#### processAliasRegistration

    protected void processAliasRegistration(Element ele)

Process the given alias element, registering the alias with the registry.

#### processBeanDefinition

    protected void processBeanDefinition(Element ele,
                             BeanDefinitionParserDelegate delegate)

Process the given bean element, parsing the bean definition and registering it with the registry.

#### preProcessXml

    protected void preProcessXml(Element root)

Allow the XML to be extensible by processing any custom element types first, before we start to process the bean definitions. This method is a natural extension point for any other custom pre-processing of the XML.

The default implementation is empty. Subclasses can override this method to convert custom elements into standard Spring bean definitions, for example. Implementors have access to the parser's bean definition reader and the underlying XML resource, through the corresponding accessors.

See Also:
  `getReaderContext()`

#### postProcessXml

    protected void postProcessXml(Element root)

Allow the XML to be extensible by processing any custom element types last, after we finished processing the bean definitions. This method is a natural extension point for any other custom post-processing of the XML.

The default implementation is empty. Subclasses can override this method to convert custom elements into standard Spring bean definitions, for example. Implementors have access to the parser's bean definition reader and the underlying XML resource, through the corresponding accessors.

See Also:
  `getReaderContext()`