Package org.apache.storm.redis.trident

Class WordCountLookupMapper

java.lang.Object

org.apache.storm.redis.trident.WordCountLookupMapper

All Implemented Interfaces:

Serializable, RedisLookupMapper, RedisMapper, TupleMapper

public class WordCountLookupMapper
extends Object
implements RedisLookupMapper

See Also:

• Serialized Form

Constructor Summary

Constructors

Constructor	Description
WordCountLookupMapper()

Method Summary

Modifier and Type	Method	Description
void	declareOutputFields(OutputFieldsDeclarer declarer)	declare what are the fields that this code will output.
RedisDataTypeDescription	getDataTypeDescription()	Returns descriptor which defines data type.
String	getKeyFromTuple(ITuple tuple)	Extracts key from tuple.
String	getValueFromTuple(ITuple tuple)	Extracts value from tuple.
List<Values>	toTuple(ITuple input, Object value)	Converts return value from Redis to a list of storm values that can be emitted.

Methods inherited from class java.lang.Object

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

Constructor Details

WordCountLookupMapper

public WordCountLookupMapper()

Method Details

toTuple

public List<Values> toTuple(ITuple input,
 Object value)

Description copied from interface: RedisLookupMapper

Converts return value from Redis to a list of storm values that can be emitted.

Specified by:

toTuple in interface RedisLookupMapper

Parameters:

input - the input tuple.

value - Redis query response value. Can be String, Boolean, Long regarding of data type.

Returns:

a List of storm values that can be emitted. Each item in list is emitted as an output tuple.

declareOutputFields

public void declareOutputFields(OutputFieldsDeclarer declarer)

Description copied from interface: RedisLookupMapper

declare what are the fields that this code will output.

Specified by:

declareOutputFields in interface RedisLookupMapper

Parameters:

declarer - OutputFieldsDeclarer

getDataTypeDescription

public RedisDataTypeDescription getDataTypeDescription()

Description copied from interface: RedisMapper

Returns descriptor which defines data type.

Specified by:

getDataTypeDescription in interface RedisMapper

Returns:

data type descriptor

getKeyFromTuple

public String getKeyFromTuple(ITuple tuple)

Description copied from interface: TupleMapper

Extracts key from tuple.

Specified by:

getKeyFromTuple in interface TupleMapper

Parameters:

tuple - source tuple

Returns:

key

getValueFromTuple

public String getValueFromTuple(ITuple tuple)

Description copied from interface: TupleMapper

Extracts value from tuple.

Specified by:

getValueFromTuple in interface TupleMapper

Parameters:

tuple - source tuple

Returns:

value