org.springframework.batch.sample.domain.multiline

Class AggregateItemReader<T>

java.lang.Object

org.springframework.batch.sample.domain.multiline.AggregateItemReader<T>

All Implemented Interfaces:

ItemReader<java.util.List<T>>

public class AggregateItemReader<T>
extends java.lang.Object
implements ItemReader<java.util.List<T>>

An ItemReader that delivers a list as its item, storing up objects from the injected ItemReader until they are ready to be packed out as a collection. This class must be used as a wrapper for a custom ItemReader that can identify the record boundaries. The custom reader should mark the beginning and end of records by returning an AggregateItem which responds true to its query methods is*().

This class is thread-safe (it can be used concurrently by multiple threads) as long as the ItemReader is also thread-safe.

Author:

Dave Syer

See Also:

AggregateItem.isHeader(), AggregateItem.isFooter()

Constructor Summary

Constructors

Constructor and Description
AggregateItemReader()

Method Summary

Modifier and Type	Method and Description
java.util.List<T>	read() Get the next list of records.
void	setItemReader(ItemReader<AggregateItem<T>> itemReader)

Methods inherited from class java.lang.Object

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

Constructor Detail

AggregateItemReader

public AggregateItemReader()

Method Detail

read

public java.util.List<T> read()
                       throws java.lang.Exception

Get the next list of records.

Specified by:

read in interface ItemReader<java.util.List<T>>

Returns:

T the item to be processed or null if the data source is exhausted

Throws:

ParseException - if there is a problem parsing the current record (but the next one may still be valid)

NonTransientResourceException - if there is a fatal exception in the underlying resource. After throwing this exception implementations should endeavour to return null from subsequent calls to read.

UnexpectedInputException - if there is an uncategorised problem with the input data. Assume potentially transient, so subsequent calls to read might succeed.

java.lang.Exception - if an there is a non-specific error.

See Also:

ItemReader.read()

setItemReader

public void setItemReader(ItemReader<AggregateItem<T>> itemReader)