org.apache.flink.batch.connectors.cassandra

Class CassandraInputFormatBase<OUT>

java.lang.Object

org.apache.flink.api.common.io.RichInputFormat<OUT,InputSplit>

org.apache.flink.batch.connectors.cassandra.CassandraInputFormatBase<OUT>

Type Parameters:

OUT - type of inputClass

All Implemented Interfaces:

Serializable, InputFormat<OUT,InputSplit>, NonParallelInput, InputSplitSource<InputSplit>

Direct Known Subclasses:

CassandraInputFormat, CassandraPojoInputFormat

public abstract class CassandraInputFormatBase<OUT>
extends RichInputFormat<OUT,InputSplit>
implements NonParallelInput

Base class for RichInputFormat to read data from Apache Cassandra and generate a custom Cassandra annotated object.

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
protected com.datastax.driver.core.Cluster	cluster
protected org.slf4j.Logger	logger
protected String	query
protected com.datastax.driver.core.Session	session

Constructor Summary

Constructors

Constructor and Description
CassandraInputFormatBase(String query, ClusterBuilder builder)

Method Summary

Modifier and Type	Method and Description
void	close() Closes all resources used.
void	configure(Configuration parameters) Configures this input format.
InputSplit[]	createInputSplits(int minNumSplits) Computes the input splits.
InputSplitAssigner	getInputSplitAssigner(InputSplit[] inputSplits) Returns the assigner for the input splits.
BaseStatistics	getStatistics(BaseStatistics cachedStatistics) Gets the basic statistics from the input described by this format.

Methods inherited from class org.apache.flink.api.common.io.RichInputFormat

closeInputFormat, getRuntimeContext, openInputFormat, setRuntimeContext

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.flink.api.common.io.InputFormat

nextRecord, open, reachedEnd

Field Detail

logger

protected final org.slf4j.Logger logger

query

protected final String query

cluster

protected transient com.datastax.driver.core.Cluster cluster

session

protected transient com.datastax.driver.core.Session session

Constructor Detail

CassandraInputFormatBase

public CassandraInputFormatBase(String query,
                                ClusterBuilder builder)

Method Detail

configure

public void configure(Configuration parameters)

Description copied from interface: InputFormat

Configures this input format. Since input formats are instantiated generically and hence parameterless, this method is the place where the input formats set their basic fields based on configuration values.

This method is always called first on a newly instantiated input format.

Specified by:

configure in interface InputFormat<OUT,InputSplit>

Parameters:

parameters - The configuration with all parameters (note: not the Flink config but the TaskConfig).

getStatistics

public BaseStatistics getStatistics(BaseStatistics cachedStatistics)

Description copied from interface: InputFormat

Gets the basic statistics from the input described by this format. If the input format does not know how to create those statistics, it may return null. This method optionally gets a cached version of the statistics. The input format may examine them and decide whether it directly returns them without spending effort to re-gather the statistics.

When this method is called, the input format is guaranteed to be configured.

Specified by:

getStatistics in interface InputFormat<OUT,InputSplit>

Parameters:

cachedStatistics - The statistics that were cached. May be null.

Returns:

The base statistics for the input, or null, if not available.

createInputSplits

public InputSplit[] createInputSplits(int minNumSplits)

Description copied from interface: InputSplitSource

Computes the input splits. The given minimum number of splits is a hint as to how many splits are desired.

Specified by:

createInputSplits in interface InputFormat<OUT,InputSplit>

Specified by:

createInputSplits in interface InputSplitSource<InputSplit>

Parameters:

minNumSplits - Number of minimal input splits, as a hint.

Returns:

An array of input splits.

getInputSplitAssigner

public InputSplitAssigner getInputSplitAssigner(InputSplit[] inputSplits)

Description copied from interface: InputSplitSource

Returns the assigner for the input splits. Assigner determines which parallel instance of the input format gets which input split.

Specified by:

getInputSplitAssigner in interface InputFormat<OUT,InputSplit>

Specified by:

getInputSplitAssigner in interface InputSplitSource<InputSplit>

Returns:

The input split assigner.

close

public void close()

Closes all resources used.

Specified by:

close in interface InputFormat<OUT,InputSplit>