public abstract class AbstractRankerBolt extends BaseBasicBolt
This abstract bolt provides the basic behavior of bolts that rank objects according to their count.
It uses a template method design pattern forexecute(Tuple, BasicOutputCollector)
to allow actual bolt implementations to specify how incoming tuples are processed, i.e. how the objects embedded within those tuples are retrieved and counted.Constructor and Description |
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AbstractRankerBolt() |
AbstractRankerBolt(int topN) |
AbstractRankerBolt(int topN,
int emitFrequencyInSeconds) |
Modifier and Type | Method and Description |
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void |
declareOutputFields(OutputFieldsDeclarer declarer)
Declare the output schema for all the streams of this topology.
|
void |
execute(Tuple tuple,
BasicOutputCollector collector)
This method functions as a template method (design pattern).
|
Map<String,Object> |
getComponentConfiguration()
Declare configuration specific to this component.
|
protected Rankings |
getRankings() |
cleanup, prepare
public AbstractRankerBolt()
public AbstractRankerBolt(int topN)
public AbstractRankerBolt(int topN, int emitFrequencyInSeconds)
protected Rankings getRankings()
public final void execute(Tuple tuple, BasicOutputCollector collector)
This method functions as a template method (design pattern).
public void declareOutputFields(OutputFieldsDeclarer declarer)
IComponent
Declare the output schema for all the streams of this topology.
declarer
- this is used to declare output stream ids, output fields, and whether or not each output stream is a direct streampublic Map<String,Object> getComponentConfiguration()
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
getComponentConfiguration
in interface IComponent
getComponentConfiguration
in class BaseComponent
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