Package org.apache.storm.flux.examples

Class WordCounter

java.lang.Object

org.apache.storm.topology.base.BaseComponent

org.apache.storm.topology.base.BaseBasicBolt

org.apache.storm.flux.examples.WordCounter

All Implemented Interfaces:

Serializable, IBasicBolt, IComponent

public class WordCounter
extends BaseBasicBolt

This bolt is used by the HBase example. It simply emits the first field found in the incoming tuple as "word", with a "count" of `1`.

In this case, the downstream HBase bolt handles the counting, so a value of `1` will just increment the HBase counter by one.

See Also:

• Serialized Form

Constructor Summary

Constructors

Constructor	Description
WordCounter()

Method Summary

Modifier and Type	Method	Description
void	cleanup()
void	declareOutputFields(OutputFieldsDeclarer declarer)	Declare the output schema for all the streams of this topology.
void	execute(Tuple input, BasicOutputCollector collector)	Process the input tuple and optionally emit new tuples based on the input tuple.
Map<String,Object>	getComponentConfiguration()	Declare configuration specific to this component.
void	prepare(Map<String,Object> topoConf, TopologyContext context)

Methods inherited from class java.lang.Object

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

Constructor Details

WordCounter

public WordCounter()

Method Details

prepare

public void prepare(Map<String,Object> topoConf,
 TopologyContext context)

Specified by:

prepare in interface IBasicBolt

Overrides:

prepare in class BaseBasicBolt

execute

public void execute(Tuple input,
 BasicOutputCollector collector)

Description copied from interface: IBasicBolt

Process the input tuple and optionally emit new tuples based on the input tuple.

All acking is managed for you. Throw a FailedException if you want to fail the tuple.

cleanup

public void cleanup()

Specified by:

cleanup in interface IBasicBolt

Overrides:

cleanup in class BaseBasicBolt

declareOutputFields

public void declareOutputFields(OutputFieldsDeclarer declarer)

Description copied from interface: IComponent

Declare the output schema for all the streams of this topology.

Parameters:

declarer - this is used to declare output stream ids, output fields, and whether or not each output stream is a direct stream

getComponentConfiguration

public Map<String,Object> getComponentConfiguration()

Description copied from interface: IComponent

Declare configuration specific to this component. Only a subset of the "topology.*" configs can be overridden. The component configuration can be further overridden when constructing the topology using TopologyBuilder

Specified by:

getComponentConfiguration in interface IComponent

Overrides:

getComponentConfiguration in class BaseComponent