Package org.hibernate.search.batch.jsr352.core.massindexing.step.spi

Class EntityReader

java.lang.Object

javax.batch.api.chunk.AbstractItemReader

org.hibernate.search.batch.jsr352.core.massindexing.step.spi.EntityReader

All Implemented Interfaces:

ItemReader

@Named("org.hibernate.search.jsr352.massindexing.impl.steps.lucene.EntityReader")
@HibernateSearchPartitionScoped
public class EntityReader
extends AbstractItemReader

Entity reader reads entities from database. During the open of the read stream, this reader builds a scrollable result. Then, it scrolls from one entity to another at each reading. An entity reader reaches its end when there’s no more item to read. Each reader contains only one entity type.

The reading range is restricted by the PartitionBound, which always represents as a left-closed interval. See HibernateSearchPartitionMapper for more information about these bounds.

Author:

Mincong Huang

Constructor Summary

Constructors

Constructor	Description
EntityReader()
EntityReader(String serializedCacheMode, String entityName, String serializedEntityFetchSize, String serializedCheckpointInterval, String serializedSessionClearInterval, String hql, String serializedMaxResultsPerEntity, String partitionIdStr, String serializedLowerBound, String serializedUpperBound, String indexScopeName, JobContext jobContext, StepContext stepContext)

Method Summary

Modifier and Type	Method	Description
Serializable	checkpointInfo()	The checkpointInfo method returns the current checkpoint data for this reader.
void	close()	Close operation(s) before the class destruction.
void	open(Serializable checkpointInfo)	Initialize the environment.
Object	readItem()	Read item from database using JPA.

Methods inherited from class java.lang.Object

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

Constructor Detail

EntityReader

public EntityReader()

EntityReader

public EntityReader(String serializedCacheMode,
                    String entityName,
                    String serializedEntityFetchSize,
                    String serializedCheckpointInterval,
                    String serializedSessionClearInterval,
                    String hql,
                    String serializedMaxResultsPerEntity,
                    String partitionIdStr,
                    String serializedLowerBound,
                    String serializedUpperBound,
                    String indexScopeName,
                    JobContext jobContext,
                    StepContext stepContext)

Method Detail

open

public void open(Serializable checkpointInfo)
          throws IOException,
                 ClassNotFoundException

Initialize the environment. If checkpoint does not exist, then it should be the first open. If checkpoint exists, then it isn't the first open, re-use the input object "checkpoint" as the last ID already read.

Specified by:

open in interface ItemReader

Overrides:

open in class AbstractItemReader

Parameters:

checkpointInfo - The last checkpoint info persisted in the batch runtime, previously given by checkpointInfo(). If this is the first start, then the checkpoint will be null.

Throws:

IOException

ClassNotFoundException

close

public void close()

Close operation(s) before the class destruction.

Specified by:

close in interface ItemReader

Overrides:

close in class AbstractItemReader

readItem

public Object readItem()

Read item from database using JPA. Each read, there will be only one entity fetched.

Specified by:

readItem in interface ItemReader

Specified by:

readItem in class AbstractItemReader

checkpointInfo

public Serializable checkpointInfo()

The checkpointInfo method returns the current checkpoint data for this reader. It is called before a chunk checkpoint is committed.

Specified by:

checkpointInfo in interface ItemReader

Overrides:

checkpointInfo in class AbstractItemReader

Returns:

the checkpoint info