StreamTransform (Nemo Project 0.2 API)

java.lang.Object
- org.apache.nemo.common.ir.vertex.transform.StreamTransform<T>

Type Parameters:

T - input/output type.

All Implemented Interfaces:

Serializable, Transform<T,T>
```
public final class StreamTransform<T>
extends Object
implements Transform<T,T>
```
A Transform relays input data from upstream vertex to downstream vertex promptly. This transform can be used for merging input data into the OutputCollector.

See Also:

Serialized Form

Nested Class Summary
- Nested classes/interfaces inherited from interface org.apache.nemo.common.ir.vertex.transform.Transform
  Transform.Context

Constructor Summary

Constructors
Constructor Description

StreamTransform()
Default constructor.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`close()`	Close the transform.
`void`	`onData(T element)`	On data received.
`void`	`onWatermark(Watermark watermark)`	On watermark received.
`void`	`prepare(Transform.Context context, OutputCollector<T> oc)`	Prepare the transform.
`String`	`toString()`

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

- Constructor Detail
  - StreamTransform
```
public StreamTransform()
```
    Default constructor.
- Method Detail
  - prepare
```
public void prepare(Transform.Context context,
                    OutputCollector<T> oc)
```
    Description copied from interface: Transform
    
    Prepare the transform.
    
    Specified by:
    
    prepare in interface Transform<T,T>
    
    Parameters:
    
    context - of the transform.
    
    oc - that collects outputs.
  - onData
```
public void onData(T element)
```
    Description copied from interface: Transform
    
    On data received.
    
    Specified by:
    
    onData in interface Transform<T,T>
    
    Parameters:
    
    element - data received.
  - onWatermark
```
public void onWatermark(Watermark watermark)
```
    Description copied from interface: Transform
    
    On watermark received. This method should be called for the minimum watermark among input streams (input watermark). Transform may emit collected data after receiving watermarks.
    
    Specified by:
    
    onWatermark in interface Transform<T,T>
    
    Parameters:
    
    watermark - watermark
  - close
```
public void close()
```
    Description copied from interface: Transform
    
    Close the transform.
    
    Specified by:
    
    close in interface Transform<T,T>
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object