Package io.github.kaststream.api.v2

Interface FlatMapper

All Superinterfaces:

Serializable

public interface FlatMapper
extends Serializable

Implement this interface to provide your own flat map function.

Method Summary

Modifier and Type	Method	Description
default void	close()	Tear-down method for the user code.
void	flatMap(KastRow kRow, KastCollector out, KastRowBuilder kastRowBuilder)	Your function implementation.
org.apache.avro.Schema	getProducedType(org.apache.avro.Schema schema)	Declare the data type information of the data produced by your function.
default void	open(Map<String,String> configuration, org.apache.avro.Schema schema)	Initialization method for the function.
default void	open(Map<String,String> configuration, org.apache.avro.Schema schema, Map<String,Object> meta)	Initialization method for the function.

Method Detail

flatMap

void flatMap(KastRow kRow,
             KastCollector out,
             KastRowBuilder kastRowBuilder)
      throws Exception

Your function implementation. Do what you need on the received rows.

Parameters:

kRow - the received row

out - the output row collector

Throws:

Exception - The function may throw exceptions which cause the streaming program to fail and go into recovery.

getProducedType

org.apache.avro.Schema getProducedType(org.apache.avro.Schema schema)

Declare the data type information of the data produced by your function.

Parameters:

schema - the input row schema

Returns:

the produced data typeInfo

open

default void open(Map<String,String> configuration,
                  org.apache.avro.Schema schema)
           throws Exception

Initialization method for the function.

Parameters:

configuration - The configuration containing the parameters attached to the contract

schema - the input row schema

Throws:

Exception - The function may throw exceptions which cause the streaming program to fail and go into recovery.

open

default void open(Map<String,String> configuration,
                  org.apache.avro.Schema schema,
                  Map<String,Object> meta)
           throws Exception

Initialization method for the function.

Parameters:

configuration - The configuration containing the parameters attached to the contract

schema - the input row schema

meta - the udf configuration parameters

Throws:

Exception - The function may throw exceptions which cause the streaming program to fail and go into recovery.

close

default void close()
            throws Exception

Tear-down method for the user code. It is called after the last call to the main working methods. For functions that are part of an iteration, this method will be invoked after each iteration superstep.

This method can be used for clean up work.

Throws:

Exception - The function may throw exceptions which cause the streaming program to fail and go into recovery.