org.springframework.batch.item

Class KeyValueItemWriter<K,V>

java.lang.Object

org.springframework.batch.item.KeyValueItemWriter<K,V>

All Implemented Interfaces:

ItemWriter<V>, org.springframework.beans.factory.InitializingBean

Direct Known Subclasses:

GemfireItemWriter, KafkaItemWriter

public abstract class KeyValueItemWriter<K,V>
extends java.lang.Object
implements ItemWriter<V>, org.springframework.beans.factory.InitializingBean

A base class to implement any ItemWriter that writes to a key value store using a Converter to derive a key from an item

Since:

2.2

Author:

David Turanski

Field Summary

Fields

Modifier and Type	Field and Description
protected boolean	delete
protected org.springframework.core.convert.converter.Converter<V,K>	itemKeyMapper

Constructor Summary

Constructors

Constructor and Description
KeyValueItemWriter()

Method Summary

Modifier and Type	Method and Description
void	afterPropertiesSet()
protected void	flush() Flush items to the key/value store.
protected abstract void	init() afterPropertiesSet() hook
void	setDelete(boolean delete) Sets the delete flag to have the item writer perform deletes
void	setItemKeyMapper(org.springframework.core.convert.converter.Converter<V,K> itemKeyMapper) Set the Converter to use to derive the key from the item
void	write(java.util.List<? extends V> items) Process the supplied data element.
protected abstract void	writeKeyValue(K key, V value) Subclasses implement this method to write each item to key value store

Methods inherited from class java.lang.Object

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

Field Detail

itemKeyMapper

protected org.springframework.core.convert.converter.Converter<V,K> itemKeyMapper

delete

protected boolean delete

Constructor Detail

KeyValueItemWriter

public KeyValueItemWriter()

Method Detail

write

public void write(java.util.List<? extends V> items)
           throws java.lang.Exception

Description copied from interface: ItemWriter

Process the supplied data element. Will not be called with any null items in normal operation.

Specified by:

write in interface ItemWriter<V>

Parameters:

items - items to be written

Throws:

java.lang.Exception - if there are errors. The framework will catch the exception and convert or rethrow it as appropriate.

flush

protected void flush()
              throws java.lang.Exception

Flush items to the key/value store.

Throws:

java.lang.Exception - if unable to flush items

writeKeyValue

protected abstract void writeKeyValue(K key,
                                      V value)

Subclasses implement this method to write each item to key value store

Parameters:

key - the key

value - the item

init

protected abstract void init()

afterPropertiesSet() hook

setItemKeyMapper

public void setItemKeyMapper(org.springframework.core.convert.converter.Converter<V,K> itemKeyMapper)

Set the Converter to use to derive the key from the item

Parameters:

itemKeyMapper - the Converter used to derive a key from an item.

setDelete

public void setDelete(boolean delete)

Sets the delete flag to have the item writer perform deletes

Parameters:

delete - if true ItemWriter will perform deletes, if false not to perform deletes.

afterPropertiesSet

public void afterPropertiesSet()
                        throws java.lang.Exception

Specified by:

afterPropertiesSet in interface org.springframework.beans.factory.InitializingBean

Throws:

java.lang.Exception