org.apache.beam.sdk.io.hadoop.format

Class HadoopFormatIO.Read<K,V>

java.lang.Object

org.apache.beam.sdk.transforms.PTransform<PBegin,PCollection<KV<K,V>>>

org.apache.beam.sdk.io.hadoop.format.HadoopFormatIO.Read<K,V>

Type Parameters:

K - Type of keys to be read.

V - Type of values to be read.

All Implemented Interfaces:

java.io.Serializable, HasDisplayData

Enclosing class:

HadoopFormatIO

public abstract static class HadoopFormatIO.Read<K,V>
extends PTransform<PBegin,PCollection<KV<K,V>>>

A PTransform that reads from any data source which implements Hadoop InputFormat. For e.g. Cassandra, Elasticsearch, HBase, Redis, Postgres, etc. See the class-level Javadoc on HadoopFormatIO for more information.

See Also:

HadoopFormatIO, Serialized Form

Field Summary

Fields inherited from class org.apache.beam.sdk.transforms.PTransform

name

Constructor Summary

Constructors

Constructor and Description
Read()

Method Summary

Modifier and Type	Method and Description
PCollection<KV<K,V>>	expand(PBegin input) Override this method to specify how this PTransform should be expanded on the given InputT.
abstract SerializableConfiguration	getConfiguration()
<T> Coder<T>	getDefaultCoder(TypeDescriptor<?> typeDesc, CoderRegistry coderRegistry) Returns the default coder for a given type descriptor.
abstract TypeDescriptor<?>	getinputFormatClass()
abstract TypeDescriptor<?>	getinputFormatKeyClass()
abstract TypeDescriptor<?>	getinputFormatValueClass()
abstract SimpleFunction<?,K>	getKeyTranslationFunction()
abstract TypeDescriptor<K>	getKeyTypeDescriptor()
abstract SimpleFunction<?,V>	getValueTranslationFunction()
abstract TypeDescriptor<V>	getValueTypeDescriptor()
abstract org.apache.beam.sdk.io.hadoop.format.HadoopFormatIO.Read.Builder<K,V>	toBuilder()
void	validateTransform() Validates construction of this transform.
HadoopFormatIO.Read<K,V>	withConfiguration(Configuration configuration) Reads from the source using the options provided by the given configuration.
HadoopFormatIO.Read<K,V>	withKeyTranslation(SimpleFunction<?,K> function) Transforms the keys read from the source using the given key translation function.
HadoopFormatIO.Read<K,V>	withValueTranslation(SimpleFunction<?,V> function) Transforms the values read from the source using the given value translation function.

Methods inherited from class org.apache.beam.sdk.transforms.PTransform

compose, compose, getAdditionalInputs, getDefaultOutputCoder, getDefaultOutputCoder, getDefaultOutputCoder, getKindString, getName, populateDisplayData, toString, validate

Methods inherited from class java.lang.Object

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

Constructor Detail

Read

public Read()

Method Detail

getConfiguration

@Nullable
public abstract SerializableConfiguration getConfiguration()

getKeyTranslationFunction

@Nullable
public abstract SimpleFunction<?,K> getKeyTranslationFunction()

getValueTranslationFunction

@Nullable
public abstract SimpleFunction<?,V> getValueTranslationFunction()

getKeyTypeDescriptor

@Nullable
public abstract TypeDescriptor<K> getKeyTypeDescriptor()

getValueTypeDescriptor

@Nullable
public abstract TypeDescriptor<V> getValueTypeDescriptor()

getinputFormatClass

@Nullable
public abstract TypeDescriptor<?> getinputFormatClass()

getinputFormatKeyClass

@Nullable
public abstract TypeDescriptor<?> getinputFormatKeyClass()

getinputFormatValueClass

@Nullable
public abstract TypeDescriptor<?> getinputFormatValueClass()

toBuilder

public abstract org.apache.beam.sdk.io.hadoop.format.HadoopFormatIO.Read.Builder<K,V> toBuilder()

withConfiguration

public HadoopFormatIO.Read<K,V> withConfiguration(Configuration configuration)

Reads from the source using the options provided by the given configuration.

withKeyTranslation

public HadoopFormatIO.Read<K,V> withKeyTranslation(SimpleFunction<?,K> function)

Transforms the keys read from the source using the given key translation function.

withValueTranslation

public HadoopFormatIO.Read<K,V> withValueTranslation(SimpleFunction<?,V> function)

Transforms the values read from the source using the given value translation function.

expand

public PCollection<KV<K,V>> expand(PBegin input)

Description copied from class: PTransform

Override this method to specify how this PTransform should be expanded on the given InputT.

NOTE: This method should not be called directly. Instead apply the PTransform should be applied to the InputT using the apply method.

Composite transforms, which are defined in terms of other transforms, should return the output of one of the composed transforms. Non-composite transforms, which do not apply any transforms internally, should return a new unbound output and register evaluators (via backend-specific registration methods).

Specified by:

expand in class PTransform<PBegin,PCollection<KV<K,V>>>

validateTransform

public void validateTransform()

Validates construction of this transform.

getDefaultCoder

public <T> Coder<T> getDefaultCoder(TypeDescriptor<?> typeDesc,
                                    CoderRegistry coderRegistry)

Returns the default coder for a given type descriptor. Coder Registry is queried for correct coder, if not found in Coder Registry, then check if the type descriptor provided is of type Writable, then WritableCoder is returned, else exception is thrown "Cannot find coder".