org.apache.flink.streaming.api.functions.sink

Class WriteSinkFunction<IN>

java.lang.Object

org.apache.flink.streaming.api.functions.sink.WriteSinkFunction<IN>

Type Parameters:

IN - Input tuple type

All Implemented Interfaces:

Serializable, org.apache.flink.api.common.functions.Function, SinkFunction<IN>

Direct Known Subclasses:

WriteSinkFunctionByMillis

@PublicEvolving
public abstract class WriteSinkFunction<IN>
extends Object
implements SinkFunction<IN>

Simple implementation of the SinkFunction writing tuples as simple text to the file specified by path. Tuples are collected to a list and written to the file periodically. The file specified by path is created if it does not exist, cleared if it exists before the writing.

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
protected WriteFormat<IN>	format
protected String	path
protected ArrayList<IN>	tupleList

Constructor Summary

Constructors

Constructor and Description
WriteSinkFunction(String path, WriteFormat<IN> format)

Method Summary

Modifier and Type	Method and Description
protected void	cleanFile(String path) Creates target file if it does not exist, cleans it if it exists.
void	invoke(IN tuple) Implementation of the invoke method of the SinkFunction class.
protected abstract void	resetParameters() Statements to be executed after writing a batch goes here.
protected abstract boolean	updateCondition() Condition for writing the contents of tupleList and clearing it.

Methods inherited from class java.lang.Object

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

Field Detail

path

protected final String path

tupleList

protected ArrayList<IN> tupleList

format

protected WriteFormat<IN> format

Constructor Detail

WriteSinkFunction

public WriteSinkFunction(String path,
                         WriteFormat<IN> format)

Method Detail

cleanFile

protected void cleanFile(String path)

Creates target file if it does not exist, cleans it if it exists.

Parameters:

path - is the path to the location where the tuples are written

updateCondition

protected abstract boolean updateCondition()

Condition for writing the contents of tupleList and clearing it.

Returns:

value of the updating condition

resetParameters

protected abstract void resetParameters()

Statements to be executed after writing a batch goes here.

invoke

public void invoke(IN tuple)

Implementation of the invoke method of the SinkFunction class. Collects the incoming tuples in tupleList and appends the list to the end of the target file if updateCondition() is true or the current tuple is the endTuple.

Specified by:

invoke in interface SinkFunction<IN>

Parameters:

tuple - The input record.