Class BlockingQueueItemReader<T>

java.lang.Object

org.springframework.batch.infrastructure.item.queue.BlockingQueueItemReader<T>

Type Parameters:

T - type of items to read.

All Implemented Interfaces:

ItemReader<@NonNull T>

public class BlockingQueueItemReader<T>
extends Object
implements ItemReader<@NonNull T>

This is an ItemReader that reads items from a BlockingQueue. It stops reading (i.e., returns null) if no items are available in the queue after a configurable timeout.

Since:

5.2.0

Author:

Mahmoud Ben Hassine

Constructor Summary

Constructors

Constructor	Description
BlockingQueueItemReader(BlockingQueue<T> queue)	Create a new BlockingQueueItemReader.

Method Summary

Modifier and Type	Method	Description
@Nullable T	read()	Reads a piece of input data and advance to the next one.
void	setTimeout(long timeout, TimeUnit timeUnit)	Set the reading timeout and time unit.

Methods inherited from class Object

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

Constructor Details

BlockingQueueItemReader

public BlockingQueueItemReader(BlockingQueue<T> queue)

Create a new BlockingQueueItemReader.

Parameters:

queue - the queue to read items from

Method Details

setTimeout

public void setTimeout(long timeout,
 TimeUnit timeUnit)

Set the reading timeout and time unit. Defaults to 1 second.

Parameters:

timeout - the timeout after which the reader stops reading

timeUnit - the unit of the timeout

read

public @Nullable T read()
                 throws Exception

Description copied from interface: ItemReader

Reads a piece of input data and advance to the next one. Implementations must return null at the end of the input data set. In a transactional setting, caller might get the same item twice from successive calls (or otherwise), if the first call was in a transaction that rolled back.

Specified by:

read in interface ItemReader<T>

Returns:

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

Throws:

Exception - if an error occurs.