ItemStream (Spring Batch 4.1.4.RELEASE API)

All Known Subinterfaces:
ItemStreamReader<T>, ItemStreamWriter<T>, ResourceAwareItemReaderItemStream<T>, ResourceAwareItemWriterItemStream<T>
All Known Implementing Classes:
AbstractCursorItemReader, AbstractFileItemWriter, AbstractItemCountingItemStreamItemReader, AbstractItemStreamItemReader, AbstractItemStreamItemWriter, AbstractNeo4jItemReader, AbstractPaginatedDataItemReader, AbstractPagingItemReader, AsyncItemWriter, CheckpointSupport, ChunkMessageChannelItemWriter, ChunkMonitor, CompositeItemStream, CompositeItemWriter, FlatFileItemReader, FlatFileItemWriter, HibernateCursorItemReader, HibernatePagingItemReader, ItemReaderAdapter, ItemStreamSupport, ItemWriterAdapter, JdbcCursorItemReader, JdbcPagingItemReader, JpaPagingItemReader, JsonFileItemWriter, JsonItemReader, LdifReader, MappingLdifReader, MongoItemReader, MultiResourceItemReader, MultiResourceItemWriter, Neo4jItemReader, RepositoryItemReader, ResourcesItemReader, SingleItemPeekableItemReader, StaxEventItemReader, StaxEventItemWriter, StoredProcedureItemReader, SynchronizedItemStreamReader, TradeWriter
```
public interface ItemStream
```
Marker interface defining a contract for periodically storing state and restoring from that state should an error occur.
Author:
Dave Syer, Lucas Ward

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`void`	`close()`	If any resources are needed for the stream to operate they need to be destroyed here.
`void`	`open(ExecutionContext executionContext)`	Open the stream for the provided `ExecutionContext`.
`void`	`update(ExecutionContext executionContext)`	Indicates that the execution context provided during open is about to be saved.

- Method Detail
  - open
```
void open(ExecutionContext executionContext)
   throws ItemStreamException
```
    Open the stream for the provided ExecutionContext.
    Parameters:
    executionContext - current step's ExecutionContext. Will be the executionContext from the last run of the step on a restart.
    Throws:
    java.lang.IllegalArgumentException - if context is null
    ItemStreamException
  - update
```
void update(ExecutionContext executionContext)
     throws ItemStreamException
```
    Indicates that the execution context provided during open is about to be saved. If any state is remaining, but has not been put in the context, it should be added here.
    Parameters:
    executionContext - to be updated
    Throws:
    java.lang.IllegalArgumentException - if executionContext is null.
    ItemStreamException
  - close
```
void close()
    throws ItemStreamException
```
    If any resources are needed for the stream to operate they need to be destroyed here. Once this method has been called all other methods (except open) may throw an exception.
    Throws:
    ItemStreamException