org.apache.flink.ml.common.mapper

Class Mapper

java.lang.Object

org.apache.flink.ml.common.mapper.Mapper

All Implemented Interfaces:

Serializable

Direct Known Subclasses:

ModelMapper

public abstract class Mapper
extends Object
implements Serializable

Abstract class for mappers. A mapper takes one row as input and transform it into another row.

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
protected Params	params Parameters for the Mapper.

Constructor Summary

Constructors

Constructor and Description
Mapper(TableSchema dataSchema, Params params) Construct a Mapper.

Method Summary

Modifier and Type	Method and Description
protected TableSchema	getDataSchema() Get the schema of input rows.
abstract TableSchema	getOutputSchema() Get the schema of the output rows of map(Row) method.
abstract Row	map(Row row) Map a row to a new row.

Methods inherited from class java.lang.Object

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

Field Detail

params

protected final Params params

Parameters for the Mapper. Users can set the params before the Mapper is executed.

Constructor Detail

Mapper

public Mapper(TableSchema dataSchema,
              Params params)

Construct a Mapper.

Parameters:

dataSchema - The schema of input rows.

params - The parameters for this mapper.

Method Detail

getDataSchema

protected TableSchema getDataSchema()

Get the schema of input rows.

Returns:

The schema of input rows.

map

public abstract Row map(Row row)
                 throws Exception

Map a row to a new row.

Parameters:

row - The input row.

Returns:

A new row.

Throws:

Exception - This method may throw exceptions. Throwing an exception will cause the operation to fail.

getOutputSchema

public abstract TableSchema getOutputSchema()

Get the schema of the output rows of map(Row) method.

Returns:

The table schema of the output rows of map(Row) method.