org.springframework.data.hadoop.store.dataset

Class AbstractDatasetStoreReader<T,R>

java.lang.Object

org.springframework.data.hadoop.store.dataset.AbstractDatasetStoreReader<T,R>

Type Parameters:

T - the type of entity to read

R - the type of entity in reader

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable, DataReader<T>, DataStoreReader<T>

Direct Known Subclasses:

AvroPojoDatasetStoreReader, ParquetDatasetStoreReader

public abstract class AbstractDatasetStoreReader<T,R>
extends java.lang.Object
implements DataStoreReader<T>

An abstract DataStoreReader to be extended for providing Dataset reading capabilities for specific use cases.

Author:

Janne Valkealahti

Field Summary

Fields

Modifier and Type	Field and Description
protected org.kitesdk.data.DatasetReader<R>	reader

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractDatasetStoreReader(java.lang.Class<T> entityClass, DatasetRepositoryFactory datasetRepositoryFactory, DatasetDefinition datasetDefinition) Instantiates a new abstract dataset store reader.

Method Summary

Methods

Modifier and Type	Method and Description
void	close()
protected abstract T	convertEntity(R entity) Convert entity used by a reading into a entity returned.
protected abstract org.kitesdk.data.DatasetReader<R>	createReader() Creates a DatasetReader.
protected DatasetDefinition	getDatasetDefinition() Gets the dataset definition.
protected DatasetRepositoryFactory	getDatasetRepositoryFactory() Gets the dataset repository factory.
protected java.lang.Class<T>	getEntityClass() Gets the entity class.
T	read() Read next entity from a reader.

Methods inherited from class java.lang.Object

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

Field Detail

reader

protected volatile org.kitesdk.data.DatasetReader<R> reader

Constructor Detail

AbstractDatasetStoreReader

protected AbstractDatasetStoreReader(java.lang.Class<T> entityClass,
                          DatasetRepositoryFactory datasetRepositoryFactory,
                          DatasetDefinition datasetDefinition)

Instantiates a new abstract dataset store reader.

Parameters:

entityClass - the entity class

datasetRepositoryFactory - the dataset repository factory

datasetDefinition - the dataset definition

Method Detail

read

public T read()
       throws java.io.IOException

Description copied from interface: DataReader

Read next entity from a reader.

Specified by:

read in interface DataReader<T>

Returns:

the entity or null

Throws:

java.io.IOException - if an I/O error occurs

close

public void close()
           throws java.io.IOException

Specified by:

close in interface java.io.Closeable

Specified by:

close in interface java.lang.AutoCloseable

Throws:

java.io.IOException

getEntityClass

protected java.lang.Class<T> getEntityClass()

Gets the entity class.

Returns:

the entity class

getDatasetRepositoryFactory

protected DatasetRepositoryFactory getDatasetRepositoryFactory()

Gets the dataset repository factory.

Returns:

the dataset repository factory

getDatasetDefinition

protected DatasetDefinition getDatasetDefinition()

Gets the dataset definition.

Returns:

the dataset definition

convertEntity

protected abstract T convertEntity(R entity)

Convert entity used by a reading into a entity returned.

Parameters:

entity - the entity

Returns:

the converted entity

createReader

protected abstract org.kitesdk.data.DatasetReader<R> createReader()

Creates a DatasetReader.

Returns:

the dataset reader