SupplierSource (Heron Api Documentation)

java.lang.Object
- org.apache.heron.api.topology.BaseComponent
- - org.apache.heron.api.spout.BaseRichSpout
  - - org.apache.heron.streamlet.impl.sources.StreamletSource
    - - org.apache.heron.streamlet.impl.sources.SupplierSource<R>

All Implemented Interfaces:

Serializable, IRichSpout, ISpout, IComponent, IStatefulComponent<Serializable,Serializable>
```
public class SupplierSource<R>
extends StreamletSource
```
SupplierSource is a way to wrap a supplier function inside a Heron Spout. The SupplierSource just calls the get method of the supplied function to generate the next tuple.

See Also:

Serialized Form

Field Summary
- Fields inherited from class org.apache.heron.streamlet.impl.sources.StreamletSource
  collector

Constructor Summary

Constructors
Constructor Description

SupplierSource(SerializableSupplier<R> supplier)

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`nextTuple()`	When this method is called, Heron is requesting that the Spout emit tuples to the output collector.

Methods inherited from class org.apache.heron.streamlet.impl.sources.StreamletSource
declareOutputFields, initState, open, preSave

Methods inherited from class org.apache.heron.api.spout.BaseRichSpout
ack, activate, close, deactivate, fail

Methods inherited from class org.apache.heron.api.topology.BaseComponent
getComponentConfiguration

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.apache.heron.api.topology.IComponent
getComponentConfiguration

- Constructor Detail
  - SupplierSource
```
public SupplierSource(SerializableSupplier<R> supplier)
```
- Method Detail
  - nextTuple
```
public void nextTuple()
```
    Description copied from interface: ISpout
    
    When this method is called, Heron is requesting that the Spout emit tuples to the output collector. This method should be non-blocking, so if the Spout has no tuples to emit, this method should return. nextTuple, ack, and fail are all called in a tight loop in a single thread in the spout task. When there are no tuples to emit, it is courteous to have nextTuple sleep for a short amount of time (like a single millisecond) so as not to waste too much CPU.