Package 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:
KafkaItemWriter, RedisItemWriter
public abstract class KeyValueItemWriter<K,V> extends 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, Mahmoud Ben Hassine

  • Field Summary

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

  • Constructor Summary

    Constructors
    Constructor
    Description
    KeyValueItemWriter()
     

  • Method Summary

    Modifier and Type
    Method
    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(Chunk<? 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 Details

    • itemKeyMapper

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

    • delete

      protected boolean delete

  • Constructor Details

    • KeyValueItemWriter

      public KeyValueItemWriter()

  • Method Details

    • write

      public void write(Chunk<? extends V> items) throws 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<K>
      Parameters:
      items - of items to be written. Must not be null.
      Throws:
      Exception - if there are errors. The framework will catch the exception and convert or rethrow it as appropriate.

    • flush

      protected void flush() throws Exception
      Flush items to the key/value store.
      Throws:
      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 Exception
      Specified by:
      afterPropertiesSet in interface org.springframework.beans.factory.InitializingBean
      Throws:
      Exception