Package org.apache.flink.table.runtime.keyselector

Class GenericRowDataKeySelector

java.lang.Object

org.apache.flink.table.runtime.keyselector.GenericRowDataKeySelector

All Implemented Interfaces:

Serializable, Function, KeySelector<RowData,RowData>, ResultTypeQueryable<RowData>, RowDataKeySelector

public class GenericRowDataKeySelector
extends Object
implements RowDataKeySelector

A KeySelector which will extract key from RowData. The key type is GenericRowData.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor	Description
GenericRowDataKeySelector(InternalTypeInfo<RowData> keyRowType, RowDataSerializer keySerializer, GeneratedProjection generatedProjection)

Method Summary

Modifier and Type	Method	Description
GenericRowDataKeySelector	copy()
RowData	getKey(RowData value)	User-defined function that deterministically extracts the key from an object.
InternalTypeInfo<RowData>	getProducedType()	Gets the data type (as a TypeInformation) produced by this function or input format.
void	open()

Methods inherited from class java.lang.Object

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

Constructor Detail

GenericRowDataKeySelector

public GenericRowDataKeySelector(InternalTypeInfo<RowData> keyRowType,
                                 RowDataSerializer keySerializer,
                                 GeneratedProjection generatedProjection)

Method Detail

open

public void open()

getKey

public RowData getKey(RowData value)
               throws Exception

Description copied from interface: KeySelector

User-defined function that deterministically extracts the key from an object.

For example for a class:

        public class Word {
                String word;
                int count;
        }
 

The key extractor could return the word as a key to group all Word objects by the String they contain.

The code would look like this

        public String getKey(Word w) {
                return w.word;
        }
 

Specified by:

getKey in interface KeySelector<RowData,RowData>

Parameters:

value - The object to get the key from.

Returns:

The extracted key.

Throws:

Exception - Throwing an exception will cause the execution of the respective task to fail, and trigger recovery or cancellation of the program.

getProducedType

public InternalTypeInfo<RowData> getProducedType()

Description copied from interface: ResultTypeQueryable

Gets the data type (as a TypeInformation) produced by this function or input format.

Specified by:

getProducedType in interface ResultTypeQueryable<RowData>

Specified by:

getProducedType in interface RowDataKeySelector

Returns:

The data type produced by this function or input format.

copy

public GenericRowDataKeySelector copy()