org.apache.flink.examples.java.relational

Class EmptyFieldsCountAccumulator

java.lang.Object

org.apache.flink.examples.java.relational.EmptyFieldsCountAccumulator

public class EmptyFieldsCountAccumulator
extends Object

This program filters lines from a CSV file with empty fields. In doing so, it counts the number of empty fields per column within a CSV file using a custom accumulator for vectors. In this context, empty fields are those, that at most contain whitespace characters like space and tab.

The input file is a plain text CSV file with the semicolon as field separator and double quotes as field delimiters and three columns. See getDataSet(ExecutionEnvironment, ParameterTool) for configuration.

Usage: EmptyFieldsCountAccumulator --input <path> --output <path>

This example shows how to use:

• custom accumulators
• tuple data types
• inline-defined functions
• naming large tuple types

Note: All Flink DataSet APIs are deprecated since Flink 1.18 and will be removed in a future Flink major version. You can still build your application in DataSet, but you should move to either the DataStream and/or Table API. This class is retained for testing purposes.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	EmptyFieldsCountAccumulator.EmptyFieldFilter This function filters all incoming tuples that have one or more empty fields.
static class	EmptyFieldsCountAccumulator.StringTriple It is recommended to use POJOs (Plain old Java objects) instead of TupleX for data types with many fields.
static class	EmptyFieldsCountAccumulator.VectorAccumulator This accumulator maintains a vector of counts.

Constructor Summary

Constructors

Constructor and Description
EmptyFieldsCountAccumulator()

Method Summary

Modifier and Type	Method and Description
static void	main(String[] args)

Methods inherited from class java.lang.Object

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

Constructor Detail

EmptyFieldsCountAccumulator

public EmptyFieldsCountAccumulator()

Method Detail

main

public static void main(String[] args)
                 throws Exception

Throws:

Exception