IComponent (Heron Api Documentation)

All Superinterfaces:

Serializable

All Known Subinterfaces:

IBasicBolt, IRichBolt, IRichSpout, IStatefulComponent<K,V>, IStatefulWindowedBolt<K,V>, IStreamletBasicOperator<R,T>, IStreamletRichOperator<R,T>, IStreamletWindowOperator<R,T>, ITwoPhaseStatefulComponent<K,V>, IWindowedBolt

All Known Implementing Classes:

BaseBasicBolt, BaseComponent, BaseRichBolt, BaseRichSpout, BaseStatefulWindowedBolt, BaseWindowedBolt, BasicBoltExecutor, ComplexSink, ComplexSource, ConsumerSink, FilterOperator, FlatMapOperator, GeneralReduceByKeyAndWindowOperator, GeneralReduceByKeyOperator, JoinOperator, KeyByOperator, LogSink, MapOperator, ReduceByKeyAndWindowOperator, ReduceByKeyOperator, SplitOperator, StatefulWindowedBoltExecutor, StreamletOperator, StreamletSource, StreamletWindowOperator, SupplierSource, TransformOperator, UnionOperator, WindowedBoltExecutor
```
public interface IComponent
extends Serializable
```
Common methods for all possible components in a topology. This interface is used when defining topologies using the Java API.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`void`	`declareOutputFields(OutputFieldsDeclarer declarer)`	Declare the output schema for all the streams of this topology.
`Map<String,Object>`	`getComponentConfiguration()`	Declare configuration specific to this component.

- Method Detail
  - declareOutputFields
```
void declareOutputFields(OutputFieldsDeclarer declarer)
```
    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
```
Map<String,Object> getComponentConfiguration()
```
    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