org.apache.beam.sdk.io.hadoop.inputformat

Class HadoopInputFormatIO.Read<K,V>

java.lang.Object

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

org.apache.beam.sdk.io.hadoop.inputformat.HadoopInputFormatIO.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:

HadoopInputFormatIO

public abstract static class HadoopInputFormatIO.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 HadoopInputFormatIO for more information.

See Also:

HadoopInputFormatIO, 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()
HadoopInputFormatIO.Read<K,V>	withConfiguration(org.apache.hadoop.conf.Configuration configuration) Returns a new HadoopInputFormatIO.Read that will read from the source using the options provided by the given configuration.
HadoopInputFormatIO.Read<K,V>	withKeyTranslation(SimpleFunction<?,K> function) Returns a new HadoopInputFormatIO.Read that will transform the keys read from the source using the given key translation function.
HadoopInputFormatIO.Read<K,V>	withValueTranslation(SimpleFunction<?,V> function) Returns a new HadoopInputFormatIO.Read that will transform the values read from the source using the given value translation function.

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

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()

withConfiguration

public HadoopInputFormatIO.Read<K,V> withConfiguration(org.apache.hadoop.conf.Configuration configuration)

Returns a new HadoopInputFormatIO.Read that will read from the source using the options provided by the given configuration.

Does not modify this object.

withKeyTranslation

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

Returns a new HadoopInputFormatIO.Read that will transform the keys read from the source using the given key translation function.

Does not modify this object.

withValueTranslation

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

Returns a new HadoopInputFormatIO.Read that will transform the values read from the source using the given value translation function.

Does not modify this object.

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>>>

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".