org.springframework.batch.item.xml
Class StaxEventItemReader<T>

java.lang.Object
  org.springframework.batch.item.support.AbstractItemCountingItemStreamItemReader<T>
      org.springframework.batch.item.xml.StaxEventItemReader<T>

All Implemented Interfaces:

ResourceAwareItemReaderItemStream<T>, ItemReader<T>, ItemStream, ItemStreamReader<T>, InitializingBean

public class StaxEventItemReader<T>
extends AbstractItemCountingItemStreamItemReader<T>
implements ResourceAwareItemReaderItemStream<T>, 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 AbstractItemCountingItemStreamItemReader.doOpen().
protected void	doOpen() Open resources necessary to start reading input.
protected T	doRead() Move to next fragment and map it to item.
protected void	jumpToItem(int itemIndex) Move to the given item index.
protected boolean	moveCursorToNextFragment(XMLEventReader reader) Responsible for moving the cursor before the StartElement of the fragment root.
void	setFragmentRootElementName(String fragmentRootElementName)
void	setResource(Resource resource)
void	setStrict(boolean strict) In strict mode the reader will throw an exception on AbstractItemCountingItemStreamItemReader.open(org.springframework.batch.item.ExecutionContext) if the input resource does not exist.
void	setUnmarshaller(org.springframework.oxm.Unmarshaller unmarshaller)

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

close, getCurrentItemCount, getExecutionContextUserSupport, isSaveState, open, read, setCurrentItemCount, setMaxItemCount, 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.ItemStream

close, open, update

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

read

Constructor Detail

StaxEventItemReader

public StaxEventItemReader()

Method Detail

setStrict

public void setStrict(boolean strict)

In strict mode the reader will throw an exception on AbstractItemCountingItemStreamItemReader.open(org.springframework.batch.item.ExecutionContext) if the input resource does not exist.

Parameters:

strict - false by default

setResource

public void setResource(Resource resource)

Specified by:

setResource in interface ResourceAwareItemReaderItemStream<T>

setUnmarshaller

public void setUnmarshaller(org.springframework.oxm.Unmarshaller unmarshaller)

Parameters:

unmarshaller - maps xml fragments corresponding to records to objects

setFragmentRootElementName

public void setFragmentRootElementName(String fragmentRootElementName)

Parameters:

fragmentRootElementName - name of the root element of the fragment

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(XMLEventReader reader)
                                    throws NonTransientResourceException

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.

Throws:

NonTransientResourceException - if the cursor could not be moved. This will be treated as fatal and subsequent calls to read will return null.

doClose

protected void doClose()
                throws Exception

Description copied from class: AbstractItemCountingItemStreamItemReader

Close the resources opened in AbstractItemCountingItemStreamItemReader.doOpen().

Specified by:

doClose in class AbstractItemCountingItemStreamItemReader<T>

Throws:

Exception

doOpen

protected void doOpen()
               throws Exception

Description copied from class: AbstractItemCountingItemStreamItemReader

Open resources necessary to start reading input.

Specified by:

doOpen in class AbstractItemCountingItemStreamItemReader<T>

Throws:

Exception

doRead

protected T doRead()
            throws Exception

Move to next fragment and map it to item.

Specified by:

doRead in class AbstractItemCountingItemStreamItemReader<T>

Returns:

item

Throws:

Exception

jumpToItem

protected void jumpToItem(int itemIndex)
                   throws Exception

Description copied from class: AbstractItemCountingItemStreamItemReader

Move to the given item index. Subclasses should override this method if there is a more efficient way of moving to given index than re-reading the input using AbstractItemCountingItemStreamItemReader.doRead().

Overrides:

jumpToItem in class AbstractItemCountingItemStreamItemReader<T>

Throws:

Exception