org.springframework.batch.item.xml
Class StaxEventItemReader

java.lang.Object
  org.springframework.batch.item.support.AbstractBufferedItemReaderItemStream
      org.springframework.batch.item.xml.StaxEventItemReader

All Implemented Interfaces:

ResourceAwareItemReaderItemStream, ItemReader, ItemStream, InitializingBean

public class StaxEventItemReader
extends AbstractBufferedItemReaderItemStream
implements ResourceAwareItemReaderItemStream, InitializingBean

Item reader for reading XML input based on StAX. It extracts fragments from the input XML document which correspond to records for processing. The fragments are wrapped with StartDocument and EndDocument events so that the fragments can be further processed like standalone XML documents. The implementation is *not* thread-safe.

Author:

Robert Kasanicky

Constructor Summary

StaxEventItemReader()

Method Summary

void	afterPropertiesSet() Ensure that all required dependencies for the ItemReader to run are provided after all properties have been set.
protected void	doClose() Close the resources opened in AbstractBufferedItemReaderItemStream.doOpen().
protected void	doOpen() Open resources necessary to start reading input.
protected Object	doRead() Move to next fragment and map it to item.
protected boolean	moveCursorToNextFragment(javax.xml.stream.XMLEventReader reader) Responsible for moving the cursor before the StartElement of the fragment root.
void	setFragmentDeserializer(EventReaderDeserializer eventReaderDeserializer)
void	setFragmentRootElementName(String fragmentRootElementName)
void	setResource(Resource resource)

Methods inherited from class org.springframework.batch.item.support.AbstractBufferedItemReaderItemStream

close, getCurrentItemCount, jumpToItem, mark, open, read, reset, setCurrentItemCount, setName, setSaveState, update

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.springframework.batch.item.ItemReader

mark, read, reset

Methods inherited from interface org.springframework.batch.item.ItemStream

close, open, update

Constructor Detail

StaxEventItemReader

public StaxEventItemReader()

Method Detail

setResource

public void setResource(Resource resource)

Specified by:

setResource in interface ResourceAwareItemReaderItemStream

setFragmentDeserializer

public void setFragmentDeserializer(EventReaderDeserializer eventReaderDeserializer)

Parameters:

eventReaderDeserializer - maps xml fragments corresponding to records to objects

setFragmentRootElementName

public void setFragmentRootElementName(String fragmentRootElementName)

Parameters:

fragmentRootElementName - name of the root element of the fragment TODO String can be ambiguous due to namespaces, use QName?

afterPropertiesSet

public void afterPropertiesSet()
                        throws Exception

Ensure that all required dependencies for the ItemReader to run are provided after all properties have been set.

Specified by:

afterPropertiesSet in interface InitializingBean

Throws:

IllegalArgumentException - if the Resource, FragmentDeserializer or FragmentRootElementName is null, or if the root element is empty.

IllegalStateException - if the Resource does not exist.

Exception

See Also:

InitializingBean.afterPropertiesSet()

moveCursorToNextFragment

protected boolean moveCursorToNextFragment(javax.xml.stream.XMLEventReader reader)

Responsible for moving the cursor before the StartElement of the fragment root. This implementation simply looks for the next corresponding element, it does not care about element nesting. You will need to override this method to correctly handle composite fragments.

Returns:

true if next fragment was found, false otherwise.

doClose

protected void doClose()
                throws Exception

Description copied from class: AbstractBufferedItemReaderItemStream

Close the resources opened in AbstractBufferedItemReaderItemStream.doOpen().

Specified by:

doClose in class AbstractBufferedItemReaderItemStream

Throws:

Exception

doOpen

protected void doOpen()
               throws Exception

Description copied from class: AbstractBufferedItemReaderItemStream

Open resources necessary to start reading input.

Specified by:

doOpen in class AbstractBufferedItemReaderItemStream

Throws:

Exception

doRead

protected Object doRead()
                 throws Exception

Move to next fragment and map it to item.

Specified by:

doRead in class AbstractBufferedItemReaderItemStream

Returns:

item

Throws:

Exception